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A Standard  Reference  Book 
for  Shooters,  Gunsmiths, 
Ballisticians,  Historian  s. 
Hunters  and  Collectors 


By  JULIAN  S.  HATCHER 


Major  General,  U.  S.  Army,  Retired 


HATCHER’S 

NOTEBOOK 


J I ‘ I I \ N > . n \ M . M Iv  K 

IcolmicJ  iUliuM.  The  Antericun  Ri^atiaiu  Member,  Hie 
N;i{j«Mi;il  ilo.inl  for  the  Promexion  of  Kiflc  Practice,  Mcinhcr,  I'lic  Uultei! 
States  ()lyin(>ic  (iames  Oimmirrrr.  riirrcNir.  rhe  Natiouol  Klri«  As 
social  ion  of  America.  i%)n  to  1946. 

"Disiioguished  Pistol  bhoc  ” U.  S.  Army.  Wiimcr.  U'ch* 
lev  & Sentt  Pistol  Ifophy,  Bisky.  Er^land.  1951.  V.  S.  lnN*rnatinnal  Uirtc 
'I  um>,  Ssvlh»rrland.  19*5;  Rome.  1927;  Ancuerp,  1930.  (^pt.dn,  I*.  S.  In* 
tertucu»ni[  RtHc  Bisicy.  Fnj^UnJ.  1931. 

Ldiior.  “The  Dupe  Bag,*'  Pistol  Sect  urn,  Anm  .W  thtf 
A/j/;  and  The  Anteris'in  Hifiem.vi.  19: ’ to  19;*  I ifi*  member,  United 
States  He  solver  ,\s«ocia(ion. 

Ollicer  in  Charge.  Htpcrimcntal  Dcpariincnt.  Spring H rid 
Annory,  1917.  Chid.  Machine  Gun  ami  Small  Anns  Section,  Fngmeermg 
OivKiem,  Ordnance,  Washington.  191S-  VA*c»rl;s  ,\lan«get,  Springjicid  Ann* 
ory,  I9i9*i92j.  Officer  in  Charge  vf  Small  Anns  Ammunition  Manufac- 
ture, Frankford  Arsend,  192 5- 1 92 1^.  Chid  of  Small  Arms  Division.  Tech- 
meal  Staff.  Ordnance  Deparrmenr,  W’asbingmn.  1929.  Chief  of  Small  Arms 
Division,  Marmfactxiring  Service,  Ordnance  Department,  Washiiigtuii,  1929- 
1933.  Assisiam  Ctmiiuandanr,  The  Ordnance  School.  19^7-1940.  Com- 
manding General.  I'he  Ordnance  Trainir^  Center,  1941-1942.  Chief  of 
Ordnance  Training  Service,  1942-1943.  Chief  of  Field  Service,  1943-1945. 

Distingubhed  Service  Medal,  Legion  of  Merit. 


Copyright  1947 

The  Mjlitarv  Sermce  PtuLisnsNC  Company 


FIRST  F.IrtTlON 

First  Printing,  August,  1947 
Second  Prinring,  July,  J948 
Third  Printing,  April,  1952 

SECOND  EDHION 
First  Prinring,  October,  1957 


This  maierifll  may  not  be  reproduced  by  anyone  save  a reviewer 
who  wishes  to  quote  short  extracts  in  a W4gtfz/we,  radio  or  newspaper 
review,  /Id dress  all  requests  for  other  quotations  to  the  Vuh Usher. 


Printed  in  the  United  States  of  America 
Ry  The  Tf.i.egraph  Press,  Established 
Harrislntrgy  Petmsylvania 


WHEN  ill  1946,  after  41  years  service,  \ retired  from  the  Army 
and  became  Teclmical  Editor  of  I'hc  Americm  Rifteman,  I 
collected  together  a number  of  reference  notes  for  my  own  use. 
These  proved  so  useful  to  me  that  I thought  it  would  lie  nice  to  have 
them  permanently  available  in  bonk  form,  su  1 arranged  fr)i*  their 
publication  under  the  title  of  Hntchkr’s  Noit.book. 

As  the  supply  on  hand  sold  out,  the  book  has  been  reprinred  from 
time  to  rime;  now,  nine  years  after  the  l>ook’s  first  appearance,  the 
publisher’s  stock  is  again  nearing  exliaustion,  and  it  again  becomes 
necessary  to  print  a fresh  supply.  For  chat  reason  this  seems  an  ap- 
propriate time  to  add  some  chapters  covering  additional  subjects 
which  tny  experience  as  head  of  the  National  Rifleman’s  Tcclinical 
Service  has  shown  to  he  of  interest  to  mcmbcj's  of  that  association 
and  to  readers  of  the  Ri fief  mu. 

Accordingly,  all  of  the  original  m:irerial  of  Hmchfr's  Notkbook 
has  now  been  reprinted  without  change  as  Part  One.  and  four  new 
chapters  have  been  added  ;is  Pan  Two  which  will  give  much  im- 
portant information  not  included  in  the  original  voluTue,  The  orig- 
inal index  is  retained  ac  the  end  of  Part  One  and  an  index  of  the  new 
material  appears  at  the  end  of  Part  Two. 

First  of  the  new  chapters  covers  the  development  and  adoption 
of  a new  non-corrosive  primer,  a new  rifle  and  macliinc  gun  cartridge, 
a new  service  rifle,  and  a new  all-purpose  machine  gun  by  the  Army, 
as  well  as  the  development  and  marketing  of  a number  of  new  rifle 
cartridges  by  rlie  conjmcrcial  animunidon  companies. 

The  second  new  chapter  covers  the  subject  of  explosions  and 
powder  fires,  as  well  as  the  behavior  of  am  munition  when  ir  is  ex- 
ploded, accidentally  or  otherwise,  while  it  is  not  in  a gun.  The  many 
inquiries  on  this  subject  that  1 received  from  Police  and  Fire  Depart- 
ments, state  and  municipal  .authorities,  and  from  readers  of  the 
magazine  caused  me  to  make  a large  number  of  interesting  experi- 
ments to  he  able  to  answer  their  questitms  with  certainty.  The  in- 
formation thus  developed  i.s  of  great  value,  and  is  so  important  that 
it  should  be  preserved  pcmiancnriv'  in  convenient  form  for  reference. 

The  third  new  chapter  covers  the  fascinating  and  little  understood 
subject  of  what  happeas  when  a bullet  is  fired  straight  up.  Many 
experimenters  have  fired  bullets  vertically  upwards  and  tried  to  note 
their  return  to  earth;  but  in  most  instances  such  bullets  simply 
disappear  inro  the  wild  blue  yonder  and  no  sign  of  their  return  is 


ever  detected.  The  reason  is  here  explained  and  well  documented  by 
the  resulK  of  official  tests  taken  from  Ordnance  files. 

The  fourth  chapter,  on  the  subject  of  exterior  ballistics,  is  again  the 
result  of  my  urgent  desire  to  have  available  a handy  bound  reference 
book  for  which  1 can  reach  when  I want  to  make  any  of  a nujuber 
of  simple  but  nccewary  ballistic  calculations  arising  out  of  such  ques- 
tions as— What  is  the  bailistic  coefficient  of  a newly  designed  bullet 
of  which  T have  just  received  a sample?  If  rhe  chronograph  shows 
a certain  velocity  at  25  feet  in  front  of  rhe  gun,  what  is  the  real 
muzzle  velocity?  If  it  lases  125  feet  of  its  original  velocity  in  the  first 
100  yards,  how'  m\ich  will  it  lose  in  the  next  hundred  and  the  next- 
What  will  he  its  time  of  flight  over  any  given  distance  and  how 
much  will  the  bullet  drop  below  the  line  of  departure  at  various 
ranges?  And  other  similar  questions. 

As  technical  Editor.  1 often  receive  rc<iucsts  for  the  uatue  of  a 
hook  on  exterior  ballistics  that  will  give  such  information;  and  1 nm 
always  distressed  to  have  to  reply  that  the  books  that  I vise  for  rhnr 
work  are  out  of  print  and  unobtainable.  The  ballistic  tables  and 
references  char  I use  are  contained  in  six  different  books,  and  in  this 
new  chapter  I have  endeavored  to  include  material  that  will  enable 
me  to  throw  those  six  hooks  away  and  never  miss  them. 

The  best  c.xrerior  ballistic  rabies  for  use  in  small  arms  work  arc  those 
of  Ingalls,  published  years  ago  by  the  Ordnance  Depamnent  in  the 
now  out-of-prinr  Actillcr>*  ('irciilar  M.  Ingalls’  highly  u-scful  Table  I 
has  been  included  in  full,  tog  ether  with  an  abridged  form  of  his 
Table  II.  Tn  addition  the  history  and  principles  of  exterior  bullisrics 
have  been  stated  in  a simplified  fonn,  together  with  a roinparativc 
rahularion  of  the  hard-to-find  basic  retardation  functions  as  deter- 
mined by  several  different  experimental  firings  in  various  criuntries. 

Mr.  Walter  J.  Ibme,  editor  of  The  Antcrican  Rifltnnan,  on  whose 
great  knowledge  and  excellent  judgciucnc  I rely  greatly,  has  been 
most  helpful.  Col  E.  H.  Harrison,  Ordnance  Corps,  U.S.  Army,  re- 
tired, of  The  AvteriCiW  Riflcttfim  editorial  staff,  has  made  numerous 
valuable  suggestions,  and  has  pointed  out  several  errors  in  my  work 
that  without  his  help  would  have  gone  undetected.  Mr.  Homer  S. 
Powley,  of  Shaker  Heights.  Ohio,  who  is  extremely  accomplished 
in  the  field  of  exterior  ballistics,  has  been  of  incalculable  help  to  me 
in  my  efforts  to  obtain  a better  understanding  of  this  siibiect,  and 
has  furnished  me  valuable  material  which  I have  included.  To  these 
three  men  I offer  mv  sincere  rhanks  for  the  assistance  the\"  have 
so  generously  given. 

Falls  Church,  Virginia. 

July,  1957. 


JuUAX  S.  Hstchkr, 
Major  General^  US.A.y  Retired 


ACKNOWLEDGEMENT 


It  is  a picas II  i*c  to  acknowlc^e  my  indebtedness  Co  the  many  friends 
and  assneiarcs  who  have  so  willingly  answ'cred  my  requests  for  as- 
sistance in  the  preparation  of  this  work. 

Charles  B.  Ijscer,  Editor  of  The  American  Riftem/m,  spent  much 
time  and  labor  in  reading  the  first  draft  of  the  manuscript,  and  made 
a number  of  extremely  valuable  suggestions  which  resulted  in  a com- 
plete re-arrangement  and  rewriting  of  the  hook.  Richard  Gordon 
XlcCloskcy  made  a number  of  highly  coastructivc  suggestions  as  to 
form  and  contents  which  were  most  gratefully  received  and  put  into 
execution. 

Invaluable  technical  information  and  assistance  was  freely  given  by 
a number  of  my  friends  who  will  be  mentioned  in  alphabetical  order 
as  follows!  Alvin  H.  Barr,  of  the  National  Rifle  Association  Technical 
Staff;  Lt,  Col.  Calvin  Goddard;  Maj.  J.  C Gray  and  Col.  Samuel  G. 
Green,  of  the  Ordnance  DepaitmeiU;  my  son,  Lieut  Robert  D. 
Hatcher,  now  on  active  duty  in  the  Navy;  .Mr.  Stanley  F.  Hood, 
Small  Arms  Maintenance  Expert  for  the  Ordnance  Department;  Col. 
G.  B.  Jarrett,  of  Aberdeen  Proving  Ground;  Cy>t  F.  J.  Jervey, 
retired  hero  of  the  Marne  fight  in  World  War  L now  Ordnance 
Engineer  and  ammunition  expert;  Capt.  Melvin  M.  Johnson,  U.  S. 
M.  C.  R.,  eminent  arms  designer;  Mr  Vrank  J.  Kahrs,  of  the  Reming- 
ton Arms  Co.;  Mr.  Fdwin  Pugsicy,  of  the  Winchester  Repeating 
Arms  Co.;  Maj.  J.  J.  Reen;  Cape.  Philip  B.  Sharpe;  CoL  Rene  R. 
Srudler,  Chief  of  the  Small  Arms  Division,  Ordnance  Research  & 
Development  Service;  and  my  longtime  friend  and  counselor,  Col. 
Townsend  Whelen. 

It  .vhoulcl  be  understood  that  the  opinions  given  herein  represent  niy 
own  views,  and  are  nor  necessarily  the  views  of  the  Chief  of  Ordnance 
or  of  the  War  Department. 


JULIAN  S.  HATCHER, 

Major  General,  U.S.A.,  Retired. 


Falls  Church,  Va., 
July  8,  1947. 


CONTENTS 

PART  ONE 

1.  Brief  History  of  the  Springfield  i 

2.  Brief  History  of  the  Enfield  12 

3.  Brief  History  of  the  .3o-’o6,  the  .50  Mr,  and  the  .30  Mi 

Cartridges  19 

4.  Auto  made  Gun  Mechanisms 32 

5.  Notes  on  Machine  Gnns  and  Their  Development  70 

6.  The  Military  Semiautomatic  Rifle 139 

7.  Experiments  with  Barrel  Obstructions  180 

8.  The  Strength  of  Military^  Rifles 198 

9.  Receiver  Steels  and  Heat  Treatment  212 

to.  Headspace  232 

I r.  Block  That  Kick!— Rome  Observations  on  Recoil 253 

12.  The  Theory  of  Recoil  279 

[3.  Notes  on  Gunpowder  300 

t4.  Gun  Corrosion  and  Amiminirion  Developments  334 

J5.  The  Pedersen  Device 361 

\6.  Notes  on  Set  Triggers 373 

17.  Jlandom  Notes  on  Various  Subjects  381 

1.  The  Men  Behind  the  Guns  381 

2.  Natitmal  Match  Ammunition  385 

3.  Caliber  .30  International  Match  Ammunition  388 

4.  Palma  Match  Ammunition  391 

5.  National  Match  Pistol  Ammunition  393 

6.  Dimensions  of  Cartridges  393 

7.  Accuracy  Specifications  394 

8.  Primers  394 

9.  Nomenclature  of  Cartridge  Defects  395 

10.  Interior  Ballistics  396 

11.  Muzzle  Velocity  vs.  Position  of  Cartridge  when 

Loading  39® 

12.  Effect  of  A'ariations  in  Powder  T'emperacure  on 

Muzzle  Velocity  398 


13-  Distribution  of  the  Heat  Energy  of  Powder  

f4.  Velocity  vs.  Barrel  Length  

ir.  Tables  of  Reniainin<v  Velocities,  Enersries  and  Form 
Faccors  for  Ammunition  

1 6.  Ballistic  Data  

17.  Rule  of  Computing  Ordinate  to  Trajectory  

18.  Formula  for  Wind  Deflection  

19.  Relation  Between  Muzzle  Velocity  and  Instrumental 

Velocity  

20.  Mil  vs.  Minutes  

21.  Coniparison  of  Angles  of  Departure  of  .30  ,Mi 

Ammunition  

22.  Bullet  Penetration  in  Various  -Mediums 

23.  Bullet  Lubricant  Formulae  

24.  Identification  Codes  of  German  Anns,  Atnmuniiion 

and  Optical  Insrtunient  Makers  

25.  Headstamps  on  U.  S.  Service  Cartridges  

26.  Army  Test  Procedure  and  Weapons  Nonicnclarurc 

27.  Methods  of  Measuring  Chamber  and  Bore  

28.  Reference  List  of  Numbers  .Marking  Changes  in  Gun 

Design  or  Manufacture 

29.  Overloads  in  Revolvers  

30.  Target  Mcasureinenrs  

31.  Weights  of  Weapons 

32.  Weights  and  Measures,  English  and  Metric . 

33.  American  and  Foreign  Caliber  Equivalents  

34.  Value  of  for  'rcmperatiirc  and  Pressures  .... 

0 

35.  Cartridge  Dimensions  and  Identification  Tables 

j8.  Record  of  Accidents  to  the  U.  S.  Rifle  M 1903,  1917  to  1929 
Index  


399 

399 

400 

401 
403 

403 

404 

404 

405 
405 

408 

409 
4j6 
4t6 
419 

421 

422 

422 
4M 

423 
427 

429 

4V 

442 

4R3 


PART  TWO 

t9.  Recent  Developments  

20.  Bullets  From  the  Skv 

21.  Explosions  and  Powder  Fires 

22.  Exterior  Ballistics  

Index  


491 

51  ^ 

520 

542 

627 


PART  ONE 


I 


Brief  History  of  the  Springfield  U.  S. 
Rifle,  Caliber  .30,  Model  of  1903 

IX  die  Spanish  American  War  of  1898,  our  Army  was  armed 
partly  with  Krag  Jorgensen  .30  caliber  repeaters  and  partly  with 
the  old  .45  caliber  opringfield  single  shots,  while  the  Navy  used  the 
Lee  Straight  Pull  rifles  in  a calib^er  called  6 mni  U.S.N.,  which  in 
inches  was  equal  co  .236  caliber. 

The  Mauser  rifles  used  by  the  Spaniards  proved  to  be  formidable 
wcapoiiN,  and  gained  a reputation  w-hich  caused  our  weapons  to  be 
regarded  so  critically  that  immediately  after  the  war  the  Chief  of 
Ordnance  ordered  the  preparation  of  the  pilot  model  of  a new  rifle. 
This  gun  had  a 30  inch  barrel  and  was  fitted  with  a rod  bayonet 
housed  in  the  stock  beneath  the  barrel.  The  mechanism  w'as  a modi 
tication  of  the  Mauser  action;  it  had  two  locking  lugs  at  the  front  of 
the  bolt  instead  of  one  at  the  rear  as  did  the  Krag.  The  rimmed 
cartridge  was  fed  from  5 shot  clips  into  a single  row  magazine  extend- 
ing below  the  stock. 

The  pilot  model  was  forwarded  to  the  War  Departmem  on  August 
25,  1900  for  examination,  after  which  it  was  tested  at  Springfield  by 
a board  which  on  Ocn>bcr  2,  1900,  recommended  that  the  form  of 
ihe  magazine  should  be  changed  *'io  allow  the  cartridges  to  lie  in  a 
zig-zag  manner,  thus  avoiding  the  necessity  of  having  the  magazine 
project  below  the  stock’*  and  that  the  rifle  should  use  cannelured 
cartridges.  A new  model  was  then  made  which  was  basically  the 
same  as  the  M 190^  Springfield  except  that  the  barrel  was  30  inches 
long  and  the  rod  bayonet  was  used.  After  test,  this  rifle  was  ap- 
proved for  experimental  manufacture  as  the  Model  of  1901. 

The  construction  of  5000  of  these  guns  was  authorized,  bnr  first 
the  machinery  had  to  he  changed,  and  this  took  a long  tinie,  so  it  was 
not  until  April  7,  1902  that  an  appropriation  of  81700  was  made  for 
the  manufacture  of  100  experimental  rifles.  (Thirty  years  later  an 
order  was  given  for  the  production  of  80  experimental  Garands  at 
$1000  apiece.) 

The  !oo  rifles  were  tested  at  Springfield  Armory  on  Feb.  r6,  1903, 
by  a board  which  recommended  that  the  barrel  and  bayonet  each  be 
shortened  six  inches  to  permit  the  gun  to  be  used  by  the  mounted 
services  as  well  as  by  the  Infantry,  and  thus  avoid  the  necessity  for 
a carbine. 


I 


2 


Hatcher’s  Notebook 


On  the  recommendation  of  Brigadier  General  William  Qozier, 
Chief  of  Ordnance,  this  new  model  was  on  June  19,  J90J,  approved 
as  standard  by  the  Secretary  of  War  and  desigtiated  as  the  U.  S. 
Magazine  Rifle,  Model  of  1903,  Caliber  .30. 

On  June  20,  1905,  orders  were  given  to  begin  immediately  the 
manufacture  of  the  fixtures,  dies,  cools  gauges,  etc.,  required  for 
making  225  of  these  rifles  per  8 hour  day  ac  Springfield  Armory  and 
125  per  8 hour  day  ac  Rock  Isbnd  Arsenal.  The  following  month 
these  instructions  were  changed  to  direct  the  manufacture  of  suflicient 
fixtures,  etc.,  for  making  400  rifles  per  8 hour  day  at  Springfield 
Armory. 

These  fixtures,  etc.,  were  made  wich  such  rapidity  that  quantity 
production  of  the  rifles  wa.s  begun  in  November,  1904,  and  cnnrimied 
without  intermption  until  after  the  close  of  W’orld  War  I. 

Various  changes  were  made  from  time  to  time  in  the  components 
of  the  rifle  and  the  methods  of  manufacture,  some  of  the  more  im- 
portant of  which  were  as  follows: 

During  the  fiscalyear  of  1904,  the  first  year  of  manufacture,  30,503 
rifles  were  made,  these  had  the  rod  bayonet  and  claw'-hauimcr  rear 
sight.  During  this  period  the  cocking  piece  and  safety  lock  were 
redesigned  so  that  the  rifle  might  more  satisfactorily  meet  the  re- 
quirements imposed  by  the  Infantry  Drill  Regulations  of  that  time. 

During  the  fiscal  year  1905,  (starting  July  1,  <904)  43t9<^5 
with  rod  bayonet^  were  made.  On  Jan.  11,  (905,  work  on  die  rod 
bayonet  was  stopped,  following  a letter  dated  Jan.  4,  1905,  from 
President  Theodore  Roosevelt  to  the  Secretary  of  War,  which  stated 
in  part:  “I  iiiibc  say  I think  the  rod  bayonet  about  as  poor  an  in- 
vention as  I ever  saw.  As  you  observed,  it  broke  off  as  soon  as  hit 
with  even  moderate  violence.  It  would  have  no  moral  effect  and 
mighty  bide  physical  effect.  . . . This  ramrod  bayonet  business 
does  not  make  me  chink  we  can  afford  to  trust  too  much  to 
theory  . , 

The  Army  was  then  experimenting  with  a trowel  shaped  com- 
bination bayonet  and  intrenching  tool,  but  this  idea  was  dropped, 
and  a knife  bayonet  was  approved  on  April  3,  1905  by  Secretary  of 
War  Howard 'Taft  as  the  Model  of  1905.  All  rifles  were  altered 
to  take  this  new  bayonet. 

In  this  period  also,  all  work  on  the  rear  sight  was  suspended  pend- 
ing the  outcome  of  trials  of  an  improved  sight,  which  was  finally 
adopted.  All  rifles  equipped  with  the  old  sight  were  changed  so  as 
to  have  the  improved  model. 

The  cartridge  used  with  this  gun  was  known  as  the  Ball  Cartridge, 
Caliber  .30,  Model  of  1903.  It  had  a rimless  case  and  a 220  grain 
round  nosed  full  metal  jacketed  buUcc,  with  a muzzle  velocity  of 
2300  feet  per  second.  In  the  meantime,  experiments  had  been  under- 
way with  a sharp  pointed  bullet  of  lighter  weight  and  higher  velocity. 


3 


The  Springfield,  U.  S.  Rifle,  Model  1903 

On  October  15,  this  improved  cartric^  was  approved  by  the  Secre- 
tary of  War,  under  the  designation  of  Cartridge,  Caliber  .30,  Model 
of  1906.  It  had  the  same  case  as  the  older  one,  except  that  the  neck 
was  shortened  .07  inch;  the  bullet  was  of  the  sharp  pointed  or  so- 
called  spitzer  type,  weighing  150  grains,  and  having  a muzzle  velocity 
of  2700  feet  per  second. 

This  sharp  pointed  bullet  did  not  extend  as  far  forward  as  did 
the  older  round  nosed  one,  and  it  therefore  became  necessary  to 
alter  the  design  of  the  bullet  seat  in  the  barrel  of  the  rifle  to  fit  the 
changed  bullet  contour.  During  the  11  ion  tits  of  November  and 
December  1906  and  January  and  February  1907,  no  rifles  were  as- 
sembled, owing  to  the  necesaty  of  lechambering  the  barrels  to  fit  the 
changed  ammunition.  All  rifles  previously  made  were  afterward 
brought  back  to  the  Armory  and  rcchambcrcd.  I'his  was  done  by 
taking  out  the  barrels,  cutting  them  off  at  the  rear  end  for  a distance 
of  two  threads  of  the  brccch  screw  (two  tenths  of  an  inch),  re- 
threading,  putting  back  the  barrels,  and  then  reaming  the  chamber 
to  the  new  si^e. 

Up  to  the  beginning  of  World  War  I,  there  had  been  manufactured 
at  Springfleld  Armorv  a grand  total  of  60^,924  rifles.  In  addition 
there  had  been  manu/actuxed  nearly  a third  as  many  at  Rock  Island 
Arsenal,  using  tools,  fixtures,  gauges,  etc.,  made  at  Springfield  Armory 
and  furnished  to  Rock  Island 

The  production  of  the  M 1903  Springfield  Rifle  from  its  adoption 
up  until  the  beginning  of  W'orld  war  I was  as  follows: 

KLscal  Year  of  1904  (July  1,  1903  to  July  1,  i9<i4)  30,503  rifles 


U H 

4$ 

1905 

43i9<>5 

44 

a 

ii 

1906 

97,603 

44 

<4  a 

a 

1907 

102,1  t6 

44 

<4  a 

a 

1908 

62,565 

(I 

a a 

It 

1909 

25,662 

44 

44  44 

44 

1910 

46,797 

44 

a u 

It 

191 1 

49.697 

i4 

a u 

It 

1912 

35.179 

a ii 

41 

1913 

38.070 

u 

44  u 

41 

1914 

26,545 

it 

a u 

i< 

1915 

25.977 

4i  (4 

4( 

1916 

13,631 

it 

a 

44 

J917  to  declaration  of  War,  Apr.  6,  1917  8,674 

It 

production  by 
Page  6. 

months  during  the  War  of  i 

917-1918  is  given  on 

On  Februarv 

20,  1918,  at  rifle  No.  800,000, 

a major  chang 

e was 

made  in  the  heat  treatment  of  the  receiver  and  holt,  which  resulted 

m a rifle  of  far  greater  strength  than  before. 

On  May  u,  1918,  at  receiver  No.  285,507,  Rock  Island  Arsenal 


4 


I I N K.MI  HS  \oi  KK<K)K 


5 


The  Springfiei.d,  U.  S.  Rifle,  Model  1903 

adopted  an  improved  heat  treatment  for  carboti  steel  M 1903  receivers 
and  bolts.  Around  August  1,  1918,  at  about  receiver  No.  319,921,  char 
arsenal  began  using  nickel  steel  for  part  of  the  production  of  receivers 
and  boles,  but  at  the  same  lime  continued  to  make  these  parts  of  carbon 
steel  also. 

On  April  1,  1927,  at  rifle  No.  1,275,767,  Springfield  Armory 
changed  the  material  in  the  bolt  and  receiver  to  nickel  steel.  The 
receivers  in  this  series,  while  not  quite  as  strong  as  the  double  heat 
treated  ones  which  preceded  them,  still  had  ample  strength,  and  the 
manufacture  was  simpler,  as  the  complicated  double  heat  treatment 
was  avoided.  In  changing  to  the  nickel  steel,  another  advantage  of  the 
double  beat  treated  receivers  and  bolts  was  lost,  and  this  was  the 
surface  skin  of  very  hard  metal  which  gave  a superb  wearing  surface, 
and  made  for  a very  smooth  working  acrion,  without  the  ‘ stickiness” 
of  the  relatively  soft  nickel  steel.  These  nickel  steel  aciiuns,  are,  how- 
ever, highly  satisfactory,  everything  considered.  In  the  rare  event  of 
a failure,  it  occurs  by  a gradual  stretching  rather  chan  by  a sudden 
nipt  lire. 

Nickel  steel  receivers  and  bolts  of  rifles  nniiibered  in  the  3,000,000 
series  made  by  the  Remington  Arms  Co.  during  World  War  II  were 
surface  c.iiburi/.cd,  making  them  ijuite  hard  on  the  outside  and  thus 
avoiding  the  stickiness  above  mentioned. 

During  the  years  after  World  War  1,  it  was  the  custom  to  iiivtUe 
lip  each  year  several  thousand  rifles  which  were  especially  selected  fm* 
use  nr  the  National  Matches.  In  general  these  were  the  regular  rides, 
with  star-gauged  barrels,  which  simply  means  that  the  barrels  were 
measured  with  a device  called  a star-gauge,  so  that  any  not  within 


MAKLUS  or  KIFLH  HISTORY 

"Major  Hiitcher.  explaining  lo  Experc  Stoik  Maker  Taylor,  the  detailn  of 
(he  new  .22  calibre  Sprin^^eld. 

"About  the  time  chat  Furo|>e  biased  into  war,  a yoiini;  officer  of  iliu  United 
States  Army  was  becoming  koowti  us  an  auibonty  up  rapid  firers.  As  the  war 
jirogressed,  he  turned  his  attcoiioa  to  militan*  small  arms,  and  havinj$  been 
interested  io  rifle  and  pistol  shiMUtni;  all  his  life,  soon  became  even  a nK)te 
prominent  human  factor  in  the  developmeot  of  our  army  rifles  than  be  had  been 
lit  Itis  work  with  machine  ^uns. 

"For  (he  three  years  past,  which  have  seen  the  greatest  strides  made  in  per* 
feeling  the  most  accurate  of  weap<His  fur  our  riflemen,  Major  Julian  S.  Hatcher  has 
been  actively  concerned  with  the  production  of  super'accurate  rifles  at  SprtP|;fleU{ 
Armory.  He  has  served  with  the  Ordnance  brandi  of  the  National  Match  Staffs 
of  1918.  1919,  192c  and  1921,  has  personally  competed  in  the  matches  and 
applied  his  practical  knowledge  of  the  needs  of  ibe  rifleman,  thus  gained,  to  the 
]>roblcm  of  produdne  for  the  Naiiooal  and  Imeroaiional  Matches  ihe  best  pos* 
sibfe  weapons.  Tn  addition.  Major  Hatcher  has  been  a member  of  three  boards 
appointed  to  select  ammunition  for  the  National  Matches,  and  has  conirihuied 
scieoiiflc  articles  to  the  'Encyxlopedia  Britannica,'  The  Saturday  Evening  Post,’ 
The  Scieiicific  American*  and  "Arms  and  ihe  Man.* " 

From  the  February  1,  1922  issue  of  "Arras  and  the  Man." 


6 


Hatchkr’s  Non;iwx)K 


tolerances  could  he  thrown  out.  In  addition,  the  actions  Mere  care- 
fully Hrrcd  for  good  trigircr  pull  and  the  best  possible  functioning. 

At  one  time  the  National  Match  rifles  were  made  with  headless 
cocking  pieces,  the  idea  being  to  get  a faster  firing  pin  action.  The 
regular  firing  pin  required  .0057  second  to  mvcl  through  its  sixteenths 
inch  fall,  while  the  headless  pin  required  .0049  second;  an  advantage 
which  was  very  likely  more  imaginary  than  real.  It  was  found  chat 
the  lessened  inertia  ol  chose  headless  firing  pins  encouraged  ruptured 
primers  or  primer  hlosv-backs,  and  they  were  declared  dangerous  by 
the  Ordnance  Depai  rinent  and  discontinued. 

Several  difTcrcnc  kinds  of  pistol  grip  stock  M ere  tried  on  the  National 
Match  Springficldb,  and  eventually  one  of  these,  which  had  undergone 
extensive  tests  by  the  service  boards  was  adopted  as  srandard  in  place 
of  the  old  straight  grip  stock.  This  new  stock  was  the  one  submitted 
for  test  under  the  designation  of  **Typc  C.'*  Besides  having  a pistol 
grip,  it  omitted  the  finger  grooves  on  the  sides  of  the  stock. 

This  was  standardized  on  March  15,  192H,  by  Ordnance  Dimmit  tee 
.Minute  No.  6860,  and  the  rifle  so  altered  was  known  as  the  M 190^  .Ai. 
At,  of  course,  stands  in  Army  nomenclature  fur  AJceracion  1. 

Alteration  2 js  one  which  is  not  seen  by  the  ordinary  user  of  the 
M K;oy  It  is  a stripped  barrel  and  action  used  inside  a tank  cannon 
for  siilicalibcr  practice;  ilie  only  interest  it  has  here  is  to  let  the  reader 
know  what  the  M kjo^  A 2 is,  and  so  fill  the  gap  in  the  record. 

Along  about  the  <9ps,  the  Ordnance  Department  made  up  a few 
thousand  Springfield  rifles  with  sporting  stocks  and  Lyman  No.  48 
rear  sights  for  sale  to  the  member.^  of  the  National  Kiflc  Association. 
This  was  known  as  the  Rifle,  Caliber  .50,  M 1905,  Styde  N.R.A. 

Some  heavy  barrelled  target  rifles  were  also  made  up  on  spurting 
type  stocks,  Ibcse  were  known  as  the  Rifle,  Caliber  .30,  M 1903, 
Style  'r. 

Occasionally  a Springfield  M 1903  will  he  seen  chat  has  an  ejection 
port  in  the  left  side  of  the  receiver,  and  the  words  Mark  I on  the 
receiver  ring.  This  is  one  of  the  rifles  that  was  made  up  for  use  with 
the  Pedersen  Device  during  the  latter  part  of  W'orld  War  I. 

During  the  early  1930's,  the  rifle  production  at  Springfield  Armory 
was  confined  to  replacement  parts  for  use  in  overhaul,  plus  a few^ 
National  iMatch  Rifles  assembled  in  rhasc  years  when  the  matches 
were  held.  By  1936,  the  Armory  was  being  tooled  up  for  the  pro- 
duction of  the  G a rand,  and  no  Springfields  were  made  that  year, 
though  a few  were  made  afeer  the  tooling  w^as  completed. 

Ordnance  records  show  that  in  each  of  the  calendar  rears  in  which 
these  rifles  were  made  at  Springfield,  receivers  produced  at  the 
beginning  of  January  had  serial  numbers  according  to  the  list  which 
follows: 


r»u;  Sprinomi-:i.o,  U. 

S.  Rii  i-i:, 

Model  1903 

Serial  number  of  receiver 

Serial  number  of  receivcj' 

\'car 

Produced  ac  scan  of  Year 

Y'car 

Produced  ai  suit  of 

1907 

269,451 

1922 

1,239,641 

1908 

537,862 

1923 

i,J52.3«7 

1909 

358,085 

1924 

1,261,487 

1910 

398,276 

1925 

1,267,101 

191 1 

456,376 

1926 

1,270,301 

1912 

502,04^1 

1927 

M74-7'55 

1913 

19:8 

1,285,266 

1914 

570,56. 

<929 

1,305,90  c 

1915 

595,60. 

1930 

1,338,406 

1916 

620.1  2 1 

1931 

1,369,761 

1917 

632.826 

1932 

1,404,0:6 

1918 

761,758 

1933 

'.435.934 

J919 

1,055.092 

*934 

1,441.812 

1920 

.,162,501 

1935 

'.491.531 

192  I 

1, 211, 300 

Ill  1936,  during  rhc  tooling  up  for  the  Gaiand*  prodiicticm  <»f  the 
^rifvffficld  was  suspended,  buc  it  was  resumed  in  a small  way  in  1937. 
The  last  receiver  made  was  in  October  1939,  and  it  had  the  number 
1,532,878, 

On  November  12,  1941,  the  production  of  Spring! lelds  was  again 
resumed  at  the  plant  of  the  Remington  Arms  Co.,  llion,  N.  Y-,  and 
the  first  rifle  produced  by  them  under  this  contract  was  3,000,001. 
There  are  therefore  no  Springfields  with  numbers  between  1,534,878, 
rhe  last  one  made  ac  Springfield  Armory,  and  3,000,0(31,  the  first  one 
made  on  commercial  contract  during  World  War  II. 

At  first.  Remington  made  the  ordinary  M 1903,  with  some  options 
as  to  the  form  of  stock  and  other  details.  They  started  making  re- 
ceivers and  bolts  with  the  same  3/4%  nickel  steel  used  in  the  Spring- 
fields,  afterward  changintr  to  a chrome-nickcl-molvhdenutn  steel  with 
only  .20%  to  .40%  nickel,  or  on  the  a\xragc,  about  one  tenth  as  much 
as  bad  been  used  formerly,  but  with  the  same  amount  of  chromiunu 
that  is,  .20%  to  .40%,  plus  a small  percentage  of  molybdenum. 

Tn  the  effort  to  gain  increased  production,  this  firm  inimediarely 
began  studies  and  experiments  on  design  clumges  to  make  manufacture 
simpler  and  easier.  C^e  change  was  to  omit  two  of  the  four  grooves 
used  in  rifling  the  barrel.  As  it  was  found  that  there  was  little  differ- 
ence in  the  performance  of  iIk  two  gn>ovcd  barrel  and  the  four 
grooved  one.  this  was  approved.  There  were  a number  of  other 
changes,  and  one  which  was  a distinct  improvemeur  was  rhe  provision 
of  a receiver  peep  sight. 


8 


Hatcher’s  Notebook 


On  May  21,  1942,  this  simplified  form  of  Springfield  was  approved 
for  manufacture  under  the  name  of  Rifle  Caliber  .30,  Model  of 
1905  A 3. 

Other  changes  on  the  A 3 model  arc; 

Stock.  Similar  co  that  on  the  ’03,  except  that  the  pistol  grip  is 
optional 

Bitnel  Gitard.  Replaces  the  handguard  of  the  '03,  also  covers  tiic 
space  formerly  occupied  by  the  rear  sighr. 


Forms  of  rifting  used  in  (he  Mi905  Spriogheld  Hfles. 

T.eft:  standard  four  groove  rifting  used  previous  to  1943.  The  groove^  arc  (hree 
(imes  as  wide  as  the  Jonds,  and  twist  is  <»oc  luro  in  ten  Inshes,  right  handed. 

Nominal  Uimeusiuos  are:  bore  dumeter,  .300  inch,  groove  diamvicr  .308  iudi; 
width  of  grooves^  .1767  inch.  However,  these  exia  dimensiuns  are  rarely  en* 
countered,  as  the  manufacturing  tolerances  permit  the  bore  to  be  anything  from 
.2999  inch  to  .3015  inch,  with  grooves  from  .167  indi  to  .177  indi,  and  a groove 
diameter  from  .3075  to  .3095  inch. 

night:  two  groove  ri£tng  approved  in  1943  fur  use  in  the  M1903  A3  rifle 
and  lor  replacement  barrels  for  the  M19I7  Enfield.  This  is  simply  the  four 
groove  tiding  with  two  of  the  grooves  omitted. 


Upper  Band  Assembly,  Is  made  of  sheet  metal  stampings.  I'hc 
bayonet  stud  band,  which  replaces  the  upper  band  of  the  '03,  is 
shorter,  solid  on  top,  and  has  two  bayonet  mounting  stud  hands  on 
the  bottom.  The  stacking  swivel  and  its  band  arc  stampings. 

Lo'iver  Band  and  Lo^u-'er  Band  5^ we/.  These  arc  made  fn»m  sheet 
steel  stampings. 

Trigger  Guard  Magazine  Assembly,  This  is  the  new  nomenclature 
for  the  stamped,  staked,  and  welded  magazine,  trigger  guard  and  floor 
plate. 

Front  Sight  Group.  This  is  composed  of  a flat  front  sight  pinned 
in  a slot  in  a ring  type  sight  base  which  is  keyed  and  pinned  to  the 
barrel  near  the  muzzle.  The  front  sit^hr  blades  are  furnished  in  five 
heights  from  0.477  to  0.537  inches.  In  targeting  the  rifles  the  proper 
height  of  blade  is  used  to  make  the  gun  shout  as  nearly  as  possible 
in  agreement  with  the  rear  sight  graduations. 


U.  S.  Rifle,  CaUber  .iO,  M1903A4— Soipet'a. 

Weight  (without  sight) — 8 pound?.  It>  ounces.  Sight  /nagtiificadon — 2V^  power. 

Weight  (with  Model  330  Weaver  Sight) — 9 pounds,  2 ounces.  Eye  Relief — 3 to  5 inches. 
Weight  (with  Lyman  Alaskan  Sight) — 9 pounds,  6 ounces. 


lO 


Hatcher’s  Notebook 


Butt  Plate  Group,  'fhis  Is  made  of  stampings. 

Butt  Sxvivcl  Group.  This  is  made  of  two  pkres  welded  together 
with  the  swivel  between  them. 

Bolt  Group.  VV'hilc  it  is  basicail}’^  rfic  same  as  that  for  the  1903, 
some  prts  clilTer  in  design  and  will  not  interchange  with  the  1903. 

Folto'wer  Group.  This  is  made  from  a stamping,  but  will  interchange 
with  the  same  part  from  the  1903. 

Serial  Numbers  of  /he  A 5.  Before  the  approval  of  these 
dia?iges  the  Remington  Amis  Co.  had  produced  34^^,085  M [903 
Springficlds  with  serial  numbers  lying  between  the  numbers  3,000,001 
and  3,348,085.  They  continued  to  produce  rifles,  but  these  were  now 
of  the  M tyoj  A 3 type  lying  wiriiia  blocks  of  serial  numbers  as- 
signed to  this  firm,  These  blocks  of  numbers,  nor  all  of  which  were 
used,  however,  arc  as  follows: 

3,348,086  to  3,607,999  inclusive 

3.708.000  CO  4,707,999  “ 

4.992.001  to  5,784,000  “ 

Caliber  .jo  Model  t$os  A 4.  On  June  14,  1943,  the  1903  rifle 
similar  to  the  A 3,  but  Acted  with  a telescopic  sight  was  approved  as 
the  Rifle  Caliber  .30,  Model  of  1903  A 4.  The  sight  used  was  the 
Weaver  330  3 -power  telescopic  sight,  slightly  nmdifled,  and  called 
by  the  Army  the  M 73  B 1.  Redheld  Junior  Mounts  were  used  to 
attach  these  Weaver  Telescope  sights  to  these  Sniper’s  Rifles. 

The  rifle,  caliber  .30,  M 1903  A 4,  with  Weaver  iplesct>plc  sight 
and  Rcdfidd  Junior  Mounts  was  made  bv  the  Remingum  Arms  Co., 
with  serial  numbers  in  the  bltK*ks  given  lielovv: 

3,407,088  to  3,427,087  inclusive 

4,992,001  to  4,997,045  “ 

^4, 000, 000  to  Z4,oo»,92o  “ 

Sprhigfieid  .Uade  by  L.  C.  Smith-Cororia  Typeuriters,  Inc.  This 
firm  was  the  only  other  besides  Remington  which  produced  Spring- 
field  Rifles  during  World  War  H.  This  plant  started  on  the  production 
of  M 1903  A 3 rifles  on  Oct.  24,  1942,  and  actually  began  to  turn  out 
rifles  in  volume  early  in  1943.  Blocks  of  numbers  were  assigned  to 
this  firm  as  follows: 

3.608.000  to  3,707,999  inclusive 

4.708.000  to  4,992,000  “ 

Production  at  this  plant  stopped  Febrxiaty  19,  1944,  with  rifle  No. 
4,845,831,  after  a total  of  234,580  rifles  had  been  produced.  Again  it 
will  be  noted  that  not  all  the  numbers  were  accuallv  ased,  as  the 
total  produced  does  not  agree  with  the  difference  between  the  serial 
number  of  the  first  and  the  laj>t  rifle.  This  Is  because  of  the  loss  of 
numbered  receivers  througli  rejections,  experimental  tests,  etc*. 


The  Springfieu),  U.  S.  Rifle,  Model  1903  11 

Frincipal  Dimemions  and  Weights  of  U.  S.  Magadne  Rifle, 

Aiodel  of  1903 

Barrel:  Dimensiems  Inches 

Diameter  of  bore  0.30 

Exterior  diameter  at  muzzle o.di9 

Exterior  diameter  at  breech  1.14 

Length  of  chairiber  and  b<ire *3*79 

Length  of  barrel,  total  24.006 

l.engTh  of  travel  of  bullet  in  bore 

Diameter  of  chamber,  rear  ci^  04716 

Diameter  of  chamber,  front  end  0441 

Diameter  of  neck  of  chamber,  rear  end ^*34*5 

Diameter  of  neck  of  chamber,  front  end  0.3403 

Length  of  body  of  chamber  1.793 

Length  of  shoulder  of  chamber  0.16 

Length  of  neck  of  chamber  0.396 

Length  of  chamber,  total  

Riding: 

Number  of  grooves,  4. 

Twist,  uniform,  one  turn  in  10.00 

Width  of  grooves  0.1767 

Width  of  lands  0.0389 

Depth  of  grooves 0.004 

Height  of  front  sight  a1>ove  axis  bore 1.05 

Distance  from  top  of  front  sight  to  rear  side  of  leaf,  leaf  raised  ....  22.1234 

Stock: 

Length,  with  butt  plate  40.166 

Crook,  i.c.,  distance  from  axis  of  bore  to  heel  of  butt 2.089 

Discance  from  trigger  to  butt  plate (2.74 

Length  of  gun  complete  43*^^^ 

Sight  radius  22.1254 

Widcfi  of  single  division  on  windage  scale 0.0267 

Weights  Pounds 

Barrel  2.79 

Barrel,  with  rear  sight  I wise  and  fnmt  aighr  stud 3 

Butt  plate  0.26 

Receiver  0.98 

Bolt  mechanism  t 

Magazine  and  trigger  guard  0.44 

Magazine  mechanism,  including  floor  place 0.17 

Bayonet  i 

Stock  1.58 

Hand  guard  0.13 

Front  and  rear  bands,  including  swivels 0.25 

Rear  sight,  not  including  base  0.20 

Total  weight  of  metal  pans  7.J0 

Oiler  and  thong  case  19 

Total  weight  of  arm.  including  oiler  and  thui^  case,  widi  bayonet  ....  9.69 
Total  weight  of  arm,  indudh^  oiler  and  thong  case,  without  bayonet  . . 8.69 

Weight  m compress  main*^ring i6toi8 

Trigger  pull  (measured  at  middle  point  of  bow  of  trigger)  3C0  4*/j 


II 


Brief  History  of  the  Enfield,  U.S.  Rifle 
Caliber  .30,  Model  of  1917 

IN  1907  che  British  adopted  the  Lec-Eafield  rifle  that  now  is  known 
as  the  Shore  Model  Ixe-Enlield,  (S.M.L-E.)*  using  a rimmed  car- 
tridge of  .303  caliber  that  somewhat  resembled  our  old  Krag 
cartridge. 

Three  years  later,  they  began  the  development  of  a new  rifle  to 
permit  the  use  of  a higher  powered  rimless  cartridge  with  improved 
ballistics.  By  1914  the  new  rifle  and  cartridge  had  been  perfected  and 
had  imdergnue  the  ofllcial  trials  and  was  about  to  be  adopted  under 
the  name  of  Rifle,  Eafleld,  Gdibcr  .276,  Pattern  of  1913. 

The  name  Enfield  came  from  the  fact  that  the  rifle  was  developed 
at  (he  Royal  Small  Anm  Factory  at  Enfield  Lock,  in  Middlesex,  11 
miles  north  of  London  Bridge. 

At  that  period  Britain  became  involved  in  World  War  I,  and  time 
limitations  prevented  the  intended  change  to  a new  caliber  of  small 
arms  cartridge.  As  the  need  for  rifles  was  urgent,  existing  plants  in 
England  which  had  previously  made  the  .303  S.M.L-E.  were  put  into 
high  gear  and  production  of  rhe  old  model  was  stepped  up  to  the 
maximum  possible. 

This,  however,  did  not  seem  to  be  enough,  so  Britain  turned  to 
the  U.  S.  for  further  supplies  of  small  arms,  and  placed  contracts  for 
che  establishing  of  three  huge  rifle  plants. 

These  were  the  enormous  plane  built  at  Eddystone  by  a newly  in- 
corporated firm,  the  Remington  Arms  Company  of  Delaware,  to  have 
a capacity  of  6000  rifles  per  day;  the  Winchester  Repeating  Arms 
Company,  New  Haven,  Connecticut,  2000  rifles  a dav;  and  the 
Remington  Arms  Compny,  Hion,  N.  Y.,  capacity,  3000  rifles  per  day. 

The  rifle  to  be  made  in  these  factories  was  the  Fnficld,  Pattern 
of  1914,  (the  .276  Pattern  ^3  conveited  to  take  the  .303  ca  it  ridge) 
which,  while  it  did  not  wort  as  w'cll  through  the  magazine  as  the 
rimless  cartridge,  was  and  still  is  a good  militaiy  small  arms  cartridge. 

These  plants  proved  to  be  more  or  less  of  a disappointment  to 
the  British,  for  they  were  slow'  getting  tooled  up  and  into  full  pro- 
duction, and  by  the  time  a satisfactory  volume  was  achieved,  the 
British  had  overcome  their  rifle  shortage  hy  production  in  their  home 
plants.  By  the  early  part  of  1917,  the  British  had  started  reducing 
these  contracts,  and  before  the  U.  S.  entered  the  war  on  April  6 of 
that  year,  large  lay-offs  were  taking  place,  and  the  remainder  of  the 

12 


U.  S.  Rifle,  caliber  .30,  Ml9l7. 


Hatcher’s  Notebook 


work  on  these  contracts  was  to  be  terminaced  by  about  June  i, 
June  2t,  and  July  ai,  for  the  three  plants  respectively. 

The  rifle  chat  was  being  produced  for  the  British  was  of  highly 
advanced  design,  making  it  the  best  military  rifle  used  in  World  War  I. 
Though  it  was  basically  a typical  Mauser,  it  was  improved  in  several 
respects,  and  had  a bole  and  receiver  of  high  grade  nickel  steel  that 
gave  it  a superbly  strong  action.  The  well  protected  peep  sight, 
mounted  on  the  receiver,  close  to  the  shooter’s  eye,  with  a front  siglu 
likewise  protected  by  strung  steel  ears,  gave  a sighting  combinacion 
chat  was  far  superior  to  thac  on  the  Springflcid,  and  by  a considerable 
m^in  the  best  and  most  practical  of  any  seen  in  chat  war. 

Tnc  bolt  mechanism,  like  chat  of  the  S.M.  L.-E.,  was  designed  to 
cx»ck  on  the  closing  motion.  This  was  to  make  the  excrat  tlon  easier 
in  rapid  fire,  when  the  heat  always  tightens  things  up.  With  the 
Springfield,  the  work  of  cocking  the  ^^ring  mechanism  is  added  to 
that  of  extracting  the  cartridge,  with  the  result  chat  unless  very  hard 
brass  is  used,  the  bolt  becomes  very  difficult  to  open  after  a few 
rounds  of  rapid  fire.  This  feature,  considered  a great  advantage  by 
the  British,  was  in  general  not  liked  by  our  people  who  were  thor- 
oughly used  to  the  Springfield,  which  cocks  on  the  opening  of  the 
bolt. 

The  .303  Enfield  had  a set  of  auxiliary  long  range  sights  for  musketry 
work  at  extreme  ranges.  These  were  attached  to  the  left  side  of  the 
rifle,  blit  were  omitted  in  our  M.  1917. 

When  we  entered  World  War  I on  April  6,  1917,  wc  had  on  hand 
about  fifKi,ooo  M 1903  ^ringficlds,  and  some  140,000  Krags.  Spring- 
field  Amiury  had  a capacity  of  1000  rifles  per  day,  and  Rock  Island 
Armory  could  turn  out  400  Springfield  Rifles  per  day. 

With  the  rapid  mobilization  of  our  forces,  the  need  for  rifles  was 
urgent;  our  newly  inducted  soldiers  were  actually  using  broomsticks 
instead  of  rifles  for  their  basic  drill  instruction. 

It  was  obvious  therefore  that  these  three  great  rifle  plants  should 
be  gotten  into  production  at  the  earliest  p>ssible  moment,  making 
rifles  for  our  own  use.  To  convert  them  to  make  the  Springfield  rifle 
would  take  months;  therefore  it  was  decided  chat  we  would  use  the 
Enfield,  but  chat  first  it  would  be  converted  to  use  our  . 30-^06 
cartridge. 

The  only  really'  poorly  designed  feature  on  the  rifle  was  the  ejector, 
which  had  the  C)Cctor  spring  formed  integral  with  it  by  milling  a slot 
in  one  side  and  letting  the  thin  part  thus  separated  act  as  the  spring. 
This  often  breaks  in  service,  but  fortunately  the  qector  with  its 
spring  is  cheap  and  easy  to  replace. 

For  this  rifle  the  British  used  the  Enfield  type  of  rifling,  with  wide 
lands  and  deep  grooves,  which  had  been  adopted  as  a result  of 
of  research  to  obtain  a form  of  riflii^  that  would  best  resist  the 
severe  erosion  and  barrel  wear  of  the  hot  nitro-glycerine  powder  used 


Tiir  KNriF-t-ft,  U.  S.  Riffe,  Mohdl  1917  15 

in  the  British  service.  This  had  a left  hand  twist,  with  five  lands  and 
five  grooves  of  equal  width*  the  grooves  being  .005  S inch  deep  in  a 
bore  of  .30?  inch  diameter. 

We  retained  the  Enfield  form  of  rifling*  but  changed  the  bore  and 
groove  dimensions  to  suit  our  own  bullet  diameter  of  .3086  inch,  fo 
accomplish  this  \vc  changed  the  bore  from  .303  inch  to  .300,  and 
made  the  grooves  .005  inch  deep  instead  of  .0058  as  in  the  .303. 


Left:  Form  of  ri£ing  us^  in  the  Mll>17  Infields.  l*hert  are  five  lands  and  five 
grooves,  and  lands  and  grooves  are  of  equal  width.  Nooiinal  dimensions  call  lor 
ix  bore  of  .500  indn  the  same  as  for  the  Springfield.  GriK’ves  are  jOO%  inch  deep, 
and  have  a twist  of  one  turn  in  ten  inebw*  left  handed.  During  World  War  ]l, 
many  1017  Infields  were  reborrelkd  with  two  grooved  barrels,  with  right  hand 
twist,  the  same  as  used  in  the  M 190.5  A5  as  (o  form  and  dimensions  of  riding 
and  direction  of  cwist. 

Right:  Rifling  of  (he  '*Mecford"  type*  as  used  in  the  Model  99  (1939)  7.7mm 
Japanese  rifle.  Grooves  arc  .006  deep  in  the  center,  and  have  a twist  of  1 turn 
in  9.5  inches,  tight  handed.  Other  Japanese  rifles  and  pistols  use  a similar  form 
uf  rifling.  This  Metford  rifling  was  developed  in  England,  and  was  used  in  the 
Lee-Metford  Kifle,  hut  was  superseded  by  (he  Fnfielo  form  of  rifling  to  permit 
longer  barrel  life, 

This  gave  a somewhat  tighter  barrel  than  was  used  on  the  Spring- 
field,  as  will  be  seen  when  it  is  remembered  that  in  the  M 1903  the 
grooves  are  three  times  as  uide  as  the  lands,  wliile  in  the  1917  the 
rands  and  grooves  arc  equal. 

In  the  M 1903  Springfield  the  bore  diameter  is  .300  inch,  but  only 
one  fourth  of  ic  is  left  this  size.  The  other  three  fourths  has  the  groove 
diameter  of  .30H  inch*  so  that  the  average  diameter  is  .306  inch. 

In  the  1917  rhe  bore  is  likewise  .300  inch,  but  this  comprises  one 
half  of  the  entire  inside  .surface,  instead  of  only  one  fourth  as  in 
the  Springfield.  The  other  half  consists  of  grooves,  and  as  they  are 
.005  deep,  the  equivalent  groove  diameter  is  .310  inch  though  as 
each  groove  is  opposite  to  a land  there  is  no  actual  place  where  the 
groove  diameter  can  be  measured  directly.  With  half  the  bore  having 
a diameter  of  .300  inch  and  half  having  a diameter  of  .310  inch,  the 
average  would  be  .303  inch  as  agaiasc  .306  inch  for  the  *03  Springfield. 


Hatcher's  Nai£BOoK 


i6 

WhiJe  this  is,  as  shown  above,  somewhat  tighter  than  the  rifling 
we  had  been  using  on  the  M 1903,  it  was  adopted  because  after  careful 
tests  it  seemed  to  give  the  best  results  for  that  form  of  rifling  with 
the  diameter  of  bullet  we  were  already  using. 

This  has  been  gone  into  at  some  length  because  we  so  often  see  in 
print  the  erroneous  staremenc  diat  the  1917  has  a bore  that  is  too 
loose  for  our  bullet,  because  we  “used  the  British  dimensions”  when 
wc  took  over  the  manufacture  of  the  £nfield. 

The  statement  that  this  is  not  so  is  from  (irst  hand  knowledge, 
because  during  a large  part  of  the  First  World  W'ar,  I was  Chief  of  the 
Machine  Gun  and  Small  Arms  Section,  Engineering  Division,  Ord- 
nance, or  in  other  words.  Chief  pf  Engineering  and  Design  for  Small 
Aims  for  the  Army,  and  had  personal  contact  with  this  matter  at  the 
time  these  rifles  were  being  made. 

It  is  interesting  to  note  in  this  connection,  chat  many  tests  made 
during  the  yean  tince  then  have  shown  chat  the  1917  barrels  will 
always  outwear  the  ’03  Spriogfleld  barrels.  At  this  writing,  March, 
2947,  there  is  serious  consideration  being  given  to  adopting  some  such 
form  of  rifling  as  that  on  the  Enfield  for  all  future  small  arms  nianu 
factnre. 

At  the  present  time,  not  all  19J7  Enfleld  Uifles  have  barrels  of  the 
type  described  above,  for  some  were  rcbarrelcd  with  4 groove  barrels 
having  a right  hand  twist,  of  which  the  Hi-Standard  Manufacturing 
Co.,  of  New  Haven,  Conn.,  made  61,150,  and  some  were  icbarreleS 
with  2 groove  barrels,  of  which  Johnson  Automatics,  Inc.,  of  Provi- 
dence, R.  I.,  made  1,571.  Recent  Ordnance  tests  show  that  the 
accuracy  of  all  these  barrels  is  comparable,  but  that  the  2 groove 
barrels  give  slightly  lower  pressures  with  high  powered  hunting  loads. 
The  difference  is  not,  however,  great  enough  to  give  these  two-groove 
barrels  much  advantage  over  the  four  groove  type. 

During  the  First  World  War  the  three  plants  mentioned  above 
turned  out  a total  of  2,202,429  Model  1917  F,nfields,  at  a cost  of 
approximately  |26  each. 


n 


The  Ekpield,  U.  S.  Rule,  Moi>£l  J917 

Principal  Dime/tsiovs  and  Weights  of  United  States  Rifie^ 

Cai.  .JO,  Model  tpn 


Barrel;  Dimensions  Inches 

Diameter  of  bore  >>.50 

Exterior  diameter  at  niu/yJe  o.^o 

Exterior  diameter  at  breech  

Length  of  chamber  and  bore  (from  face  of  bole  co  muzale)  :6. 

Diameter  of  chamber,  rear  end  

Diameter  of  chamber,  fr<Htr  end  <>44^ 

Diameter  of  neck  of  chamber,  rear  end  0-H25 

Diameter  of  neck  of  chair>l>er,  front  end  

Length  of  body  of  chamber  1.785 

Length  of  shoulder  of  chamber 0.1 

Length  of  neck  of  chamber  

Lcf^h  of  chamber,  total  ?.?4i 

Rifling: 

Number  of  grooves,  5. 

Twist,  uniform,  left  hand,  »»nc  lum  in  to. 

Width  of  grooves  

Width  of  lauds  

Depth  of  grooves  

Height  of  fr<mr  xighr  above  avR  of  bore  (mean)  iaj<I 

Distance  from  cop  of  front  sight  co  rear  side  of  leaf,  leaf  raised  .... 

Sr<>ck: 

Length,  with  butt  plate  4? /it 

Crook,  i.e„  distance  from  axis  of  Ixirc  10  Iwcl  of  Uiitr  j.u 

Disuuce  fniin  trigger  to  butt  place 1^.5 

Length  of  gim  complete  46,3 

Sight  radius  31.76 

Sight  radius  (battle  sight)  


Weights 

Bayonet  1 lb.  2 o/. 

Oiler  and  thong  case  ; a/. 

I'otal  weight  of  arm  with  oiler  and  thong  case  and  bayonet  ..  10  lbs.  5 i»/. 

Total  weight  of  arm  with  thong  case  without  bayonet V lbs.  ; irr. 

VV'eighc  to  compress  mainspring 16  to  18  lbs. 

Trigger  pull  (measured  at  middle  of  bow  uf  trigger)  4!^  to  6!'.  lbs. 


RIFLE  PRODUCTION  TO  NOV.  ^ 1918 


Rock 


Months 

Edds’atonc 

M'iochester 

IlioD 

Springfield 
A rmory 

Island 

^Vrscnal 

Total 

Before  Auffusr.  xoi?  

14.986 

i/>8u 

16,666 

Aug.  19:7  to  Dec.  31,  1917 

*74*»6o 

joi,)63 

*6.564 

89*479 

22,530 

414,696 

1918 

January  

«i.84^ 

39,joo 

5M55 

25,890 

7*680 

185,069 

February 

9S.J45 

32.660 

39*85* 

6,9  JU 

1*460 

180.227 

March  

68404 

4*.*oo 

49i5j8 

120 

420 

160,662 

ADfil  

8-^  ,<08 

43.600 

36*377 

170,116 

*4 

Mav 

84.9»9 

41^28 

54*477 

550 

iS5/x»4 

June  

5**995 

6,140 

619 

198,123 

Julv  



J5.700 

60415 

14.841 

1*058 

248,072 

August  

iw6,5V5 

:o/»30 

65*144 

27.020 

*»597 

220,386 

September  

11(^058 

58.027 

29*770 

}.Bi3 

153.118 

October  

53.563 

35*9*0 

3.»5« 

126^53 

Nov.  T-p.  tplS  

9.100 

16,558 

10,300 

Bu8 

67*4^^5 

Total  1.1K1.908  545 o 4*  2^5 1^* 7 47**5  J **506007 


Note:  Eddystonc,  Winchester,  and  llion  plants  turned  out  the  Enfield,  while  the  Sprkigiield  Armorv  and  the  Rock  Island  Arsenal 
produced  the  Springfield.  The  months  mailed  by  a drop  in  the  production  at  Springfield  and  at  Rocti  Island  were  months  in  which 
the  components  manufacenred  were  not  asset  1 tided  Inir  uere  uvd  for  spare  part*:. 


Ill 


A Brief  History  of  the  .30-'06,  the  .30 
Ml  and  the  .30  M2  Cartridges 

WHEN  the  M 1903  rifle  was  first  adopted,  the  cartridge  designed 
to  go  with  it  had  a rimless  case,  which,  except  for  very  minor 
changes,  is  the  same  as  that  we  have  now.  The  bullet  was  of  round 
nosed  shape,  weighing  220  grains,  with  a muzzle  velocity  of  2 3(k) 
feet  per  second. 

In  ignrt  we  adopted  a lighter  bullet  weighing  150  grains,  having 
a sharp  or  ‘Spitzer”  point,  and  with  a muzzle  velucity  of  2700  feet 
per  second.  This  bullet  had  a cu pro-nickel  jacket,  and  a core  com- 
posed of  I part  tin  to  39  parts  of  lead.  The  maximum  range  was 
given  in  the  Handbooks  as  4700  yards. 

For  use  in  long  range  matches,  the  commercial  companies  furnished 
a cartridge  with  a 180  grain  bullet,  having  better  wind  bucking 
qualities,  and  longer  range. 

In  1911  to  1913,  when  [ was  a lieutenant  of  Artillery  stationed  in 
Florida,  I did  a lot  of  shooting,  and  one  of  the  things  1 tried  was 
CO  see  how  far  I could  shoot  a Springfield  rifle  along  the  l>each.  To 
my  disappointnienc,  I just  never  could  seem  to  get  it  ro  shoot  as  far 
as  the  book  said  it  would. 

As  Chief  of  the  Machine  Gun  and  Small  Arms  Section,  Engineering 
Division,  Ordnance,  during  World  War  I,  I decided  to  solve  this 
mystery,  so  I got  one  of  my  Mexican  Border  Machine  Gun  School 
assistants,  with  whom  I had  often  collaborated  in  similar  experiments, 
and  set  hint  to  check  the  range  tables.  This  was  the  late  Lt.  Col.  Glenn 
P.  Wilhelm,  and  the  work  was  started  at  Borden  Brook  Reservoir, 
near  Springfield  Armory,  and  later  sv^s  continued  at  Miami,  then  at 
Daytona  Beach.  The  late  noted  firearms  writer,  Cape.  Edward  C. 
Ci'ossman  was  one  of  Col.  Wilhelm’s  assistants  in  this  work,  as  was 
my  brother.  Major  James  1>.  Hatcher,  65th  Artillery,  who  was  firing 
his  9-2  incli  howitzers  on  the  fortress  of  .Meiz  the  day  of  the  Amtisdee 
and  returned  to  this  country  immediately  afterward.  The  troops  he 
was  CO  take  back  to  France  were  cancelled  in  view  of  the  Armistice, 
and  while  waiting  for  another  assignment  he  worked  on  this  project 
with  Col.  Wilhelm,  This  started  him  on  a long  and  brilliant  career  in 
the  Ordnance  Department  as  a small  arms  expert. 

Col.  Wilhelm  and  his  crew  soon  found,  as  1 had  suspected  from 
mv  Florida  experience,  chat  the  .-^o-o6  bullet  would  not  go  any- 
where nearly  as  far  as  the  book  .ssud  it  would.  The  maximum  range 

*9 


20 


H .VI  cH  ek’s  N o I moo  k 


was  found  Co  be  3300  to  3400  at  an  angle  of  about  29  degrees, 

and  the  same  up  to  about  45  degrees,  after  which  the  range  began 
to  shorten. 

When  the  reason  for  this  discrepancy  was  investigated,  it  was 
found  that  the  original  cables  of  fire  had  been  made  at  Springfield 
Armory  as  a result  of  test  firings  at  Longmeadow,  along  the  Con 
nccticut  River  not  far  from  the  Ariiiorv.  Up  to  }zoo  yards,  the 
results  were  tjuicc  accurate;  beyond  this  range,  the  target  became 
harder  and  iurdcr  to  hit,  and  had  to  be  made  larger  and  larger. 
Then,  even  with  the  larifcst  pracricatilc  rargcCN,  some  hiillets  would 
be  on  and  sairie  off,  and  the  center  of  iinp.icr  hail  to  be  more  ni 
less  estimated-  When  the  range  uent  bevond  1^00  yards,  it  became 
impossible  to  get  results,  and  the  figures  on  out  to  extreme  range 
were  then  calculated  according  to  the  best  infornhirion  available  in 
those  days,  which,  however,  was  not  good  enough.  The  figure.^  for  the 
extreme  range  sy  crc  about  38%  too  big. 


teginniags  of  ilie  investigation  in  check  ihe  small  arms  range  rabies,  Borden  £ 

ok  Reservoir,  Mass.,  1918.  Center.  Li,  Col.  Glenn  P.  Vvilbelcn.  Right,  nearest  Bre 

camera,  Lc-  Col.  Wallace  L.  Clay,  tbe 


Alien  this  long  range  firing  program  was  initialed,  I felt  ceitain  ’ 

c sooner  or  later  our  forces  in  France  would  demand  greater  range  tha 

the  Small  Arms  cartridges,  as  the  Heavy  Machine  Gun  was  being  in 
eh  used  at  that  period  and  extreme  range  was  an  important  mu 

iracteristic.  I had  been  head  of  the  Machine  Gun  Schools,  first  chi 


A Brii't  lliyrouY  or  inr  Skrmci:  GsRiuim.rs  21 

on  die  Mexican  Bortkr,  then  ac  Sandy  1 look  and  later  at  Spring- 
field,  and  had  just  written  a book,  with  Wilhelm  and  Ma(onv  on 
Machine  Guns,  their  tactics,  fire  control,  etc.,  and  felt  that  when  die 
users  of  these  uuns  in  France  found  that  their  bullets  were  inferior 
in  striking  power  at  long  ranges  to  some  others,  trouble  would  start. 
So  to  be  ready  with  some  kind  of  .solution,  1 ordered  100,000  rounds 
of  iKo  grain  mulch  uiiuniinirioii,  and  made  range  firings  with  that  also. 


Col,  Wilhelm’s  Ballnac  Siaiion  at  Miami  in  1918.  CMhcer  in  center  of  top 
platform  under  range  clock  is  Major  (now  Q)lone()  .l.imes  I..  Hairhi*r,  brother 
of  the  author. 

Our  Army  had  pniccicalU  no  machine  guns  when  the  wur  started, 
so  we  armed  our  first  trot>ps  in  France  widi  British  Vickers  guns 
and  with  the  French  Hotchkiss.  I'he  Vickers  used  the  .303  Mark  VII 


Col,  Wilhelm’s  Balllstk  SiaiioQ,  Dauona,  fla..  1919.  Firing  the  .30  Caliber  rifle  with  Swiss  boai  laileJ  bulJcis  lor  ma.ximum  range. 


A Bkifi  History  ok  the  Service  Cahtridgks 

cartridge,  having  a 174  grain  flac  based  bullet,  and  the  French  Hotch- 
kiss used  the  “Ballc  a solid  bronze  boat  tailed  bullet  weighing 
about  198  grains. 

Very  soon  the  users  of  these  guns  found  that  these  bullets  had 
an  extreme  range  nearly  50%  greater  than  did  our  .30-'o6.  When  the 
Vickers  and  llotchkiss  guns  gave  way  to  the  new  Brownings,  and 
the  troops  found  that  they  could  no  longer  lay  down  barrages  at 
the  same  long  ranges  as  before,  cablegrams  came  back  hot  and  ncavy 
demanding  that  something  be  done  about  it.  Fortunately  we  were 
already  well  along  toward  finding  out  what  oar  ammunition  would 
really  do  and  what  it  wouldn’t,  and  the  reasons  for  the  condition. 
An  officer  from  my  office  who  was  in  France  on  temporary  duty 
told  them  about  the  180  grain  Match  bullets  we  were  trying,  and 
immediately  a demand  v\*as  cabled  back  for  some  of  this  to  try,  and 
it  was  sene.  We  were  then  told  that  a longer  range  for  our  small 
amis  cartridges  was  necessary  and  work  was  started  on  developing 
such  a cartridge.  Not  long  afterward  the  Armistice  of  November  ti, 
191 B put  and  end  to  the  work  for  the  time. 

In  France,  the  Fiskc  Hoard,  with  Col.  Farl  McFarland,  .Maj.  Lee 
O.  Wright,  and  Li.  Col.  J.  S.  Hatcher  as  Ordnance  Members,  visited 
each  Division,  Corps,  and  Army  headquarters  and  imerviewed  the 
Commanding  General  as  to  the  actual  characrercistics  that  should  be 
embodied  in  the  new  cartridge.  It  was  determined  chat  the  same 
ammunition  should  be  provided  for  both  rifle  and  machine  gun,  and 
that  it  should  have  the  longest  possible  range  and  the  flattest  possible 
trajectory  chat  would  still  permit  it  to  be  used  in  the  rifle. 

After  the  end  of  the  War,  the  development  of  thus  new  aninnmition 
proceeded,  with  much  advice  from  the  Infantry  Board  and  the 
Cavalry  Board,  and  with  some  of  the  experimental  types  being  tried 
our  at  the  National  Matches  at  Camp  Perrv  each  year. 

In  connection  with  these  tests  we  had  our  attention  directed  by 
Col.  r.ucian  B.  Moody  to  the  Swiss  Service  Ammunition,  which  had 
a 174  grain  boat  tailed  bullet  of  the  same  diameter,  as  our  own  service 
bullet,  chat  is,  .308  inch.  Very'  early  in  the  game  Col.  W.  L.  Clay, 
Commanding  Officer  of  Frankford  .Arsenal  conducted  a series  of 
brings  with  rhis  ammimirioa  that  showed  ii  fo  l>e  immcaselv  superior 
CO  ours  at  long  ranges.  Convenicnily  enough,  these  Swiss  bullets  could 
he  loaded  into  our  own  cases  and  fired  in  our  guns. 

Col.  Townsend  Whclen  succeeded  Col.  Clay  in  command  of  Frank- 
ford Arsenal,  and  made  up  a series  of  bullets  with  boat  tails  from  2 
degrees  on  up  to  12  degrees  taper.  These  were  fired  at  Aberdeen 
Proving  Ground,  and  it  turned  out  due  the  9 degree  bullet  gave  the 
best  performance. 

Meantime,  in  1923.  1 succeeded  Col.  Whelen  in  charge  of  the 
Frankford  Small  Arms  Ammunition  Plant,  and  in  19:5  the  type  E 
9 degree  boat  tailed  bullet  was  adopted  as  standard  for  both  rifles 


L'he  Ballistic  Station  at  Daytona,  Fla.^  1VI9.  Arrangement  for  obtaining  the  actual  angle  of  departure  by  firing  through  a scteeti 
and  measuring  the  height  of  the  bullet  bole  above  that  of  the  bore. 


A Brief  History  of  iti£  ^rvice  Cartridges 


and  machine  guns,  and  the  aninumition  was  called  the  .30  caliber 
M I.  The  bullet  had  a gilding  metal  jacket^  and  a new  and  improved 
ogive,  of  7 calibers  radhis,  giving  it  a slightly  better  form  factor 
than  the  very  similar  looking  ogive  on  the  1906  bullet.  The  muzzle 
velocity  was  2700  feet  per  second,  and  the  extreme  range  was  5900 
yards,  as  against  3400  for  the  1906, 

To  get  2700  feet  per  second  muzzle  velocity  with  this  heavy  bullet 
and  still  keep  within  a desirable  pressure  range  was  found  to  be  so 
difHculc  that  many  Iocs  of  powder  were  eliminated;  as  a result,  Col. 
Clay,  Chief  of  the  Small  Arms  Division,  pushed  through  a reduction 
of  the  velocity  to  2640  f.  s.  at  the  muz^c  or  2595  at  7B  feet.  This 
reduced  the  extreme  range  to  about  5500  yards. 

The  old  .30-'o6  bullet  had  been  made  with  a core  uf  29  parts  lead 
to  I part  tin;  this  was  found  to  be  too  soft  for  the  boat  tailed  bullet, 
whicn,  in  the  early  samples  at  least,  seemed  to  require  a very  hard 
core,  so  the  metal  used  was  1 part  antimony  to  7 parts  lead.  The 
.J0-O6  bullet  had  a cupro-nickcl  jacket;  the  had  one  of  gilding 
metal,  hence  there  was  no  difficulty  in  distinguishing  between  them 
by  appearance.  The  bullet  on  the  ’06  looked  silvery,  the  Mi  looked 
like  gold. 

At  this  time  we  had  cn  hand  about  two  billion  of  the  war-time 
.30  *06  cartridges,  and  as  ammunition  is  perishable,  the  policy  was  to 
use  up  the  oldest  ammunition  first,  keeping  the  newer  for  war  reserve. 
Thus  the  shooters  on  Army,  National  Guard  and  Civilian  rifle  ranges 
had  to  use  the  old  war  time  stuff,  while  wishing  for  the  happy  day  to 
come  when  they  could  get  some  of  the  good  new  ammunition  to  use. 

Finally  about  193d  that  wished-for  day  arrived,  and  with  it 
trouble  of  an  unexpected  sort.  The  new  ammunition  had  so  much 
longer  range  and  carrying  power  that  it  began  to  shoot  beyond  the 

Erevioas  danger  zones  of  the  existing  ranges.  TTic  National  Guard 
ureau  then  requested  the  War  Department  to  make  up  some  ammu- 
nition like  the  old  1906,  to  use  on  the  restricted  ranges,  and  the  order 
was  given  to  make  up  10,000,000  rounds  of  it. 

This  short  range  ammunition  was  made  as  much  like  the  1906  as 
possible.  It  had  a 150  grain  flat  base  bullet,  but  the  jacket  was  of 
course  made  of  gilding  metal  instead  of  the  old  cupro-nickel.  It  was, 
however,  colored  to  look  like  the  1906  by  the  use  of  a stannic  stain, 
so  it  could  be  de  distinguished  from  the  M i.  The  ogive  was  of  the 
same  shape  as  the  M i,  and  differed  a bit  from  the  shape  of  the  1906, 
but  the  difference  was  so  slight  as  to  be  imperceptible. 

Some  of  this  ammunition  reached  the  Service  Boards,  which  by  now 
had  lost  all  of  the  old  World  War  1 itiachine  gunners  who  so  keenly 
felt  the  inadequacy  of  our  ammunition  in  1918.  Our  soldiers  liked  the 
lessened  recoil  of  the  new  ammunition.  More  rounds  conld  be  carried 
for  the  same  weight,  etc.,  so  the  su^cstion  was  made  and  carried 
through  that  it  should  be  substituted  for  the  M i.  In  1940  this  ammu- 


WATERPROOFJNG  APPUEO  IN 
NECK  BEFORE  LOADING. 


PELLET 


4 t 


CUP,  PRIMER- 


NOTE- 


.006 

-.006 


ANVIL  “ 

SEAL,  CASE  VENT 


CASE 


-.04 

3.34 


POWDER  CHAROe  TO  GIVE  AN 
INSTRUMENTAL  V€  LOCI  TV  Of 


2740  230  f$.  AT  Td’fROM 
MUZZLE  OF  RIFLE. 


M2  1.125  - .04^ 
'm2  alternative 


DISC 


PRIMER  TO  6£  SECURED  IN  POCKET  6Y  A 
CIRCULAR  CRIMP  JOINT  BETWEEN  WALLS 
OF  PRIMER  ANT5  POCKET  WATERPROOFED 
WTTH  A VISIBLE  MATERIAL 


CRMPED  AFTER  BULLET  IS  INSERTED 
-015 

2.494 ^ 

CARTRIDGE  BALL  CAL  .30M2 
a M2  ALTERNATIVE 


BULLET  INSERTED  BV 
PRESSURE  ON  POINT 


SLUG 


JACKET 


Cartridge,  Ball,  cal.  .30  M2  (Glided)  and  M2  alcemative  (Sieel  Socketed). 


+j0005 

M2093h- 


2.494 


for  caJiber  .30  Service  <Iartrid|;e. 


i 


-.0010 

.3085 


M2  1.123 -.040 


CANNELURE  LOCATED  TQ  SUIT 

OVERALL  LENGTH  OF  CARTRIDGE 
KNURLING  TO  SUIT  MFC'R  S.  PRACTICE 

/!?■ 


2.IR.--05 
, (7CAL.) 


SLUG 


JLLET 


.30  M2. 


MAX. 


A Brief  History  of  the  Servicts  Cakikiuges  29 

nicion  with  some  slight  funlicr  changes,  was  standardized  as  Cartridge, 
Ball,  Caliber  .30  M 2. 

By  the  time  this  ankmuniciun  was  standardized,  tin  and  antimony 
were  getting  scarce,  and  it  was  found  that  it  was  satisfactory  to 
make  the  bmlet  core  of  lead  without  the  addition  of  any  alloying 
material.  As  the  lead  used  is  secondary  lead,  that  is,  reclaimed  from 
batteries,  etc.,  it  will  have  some  hardening  material  in  it,  but  not 
much.  Tliis  results  in  a slightly  increased  bullet  weight  of  152  grains 
instead  of  1 50.  The  muzzle  velocity  was  also  boosted  from  2700  f.  s. 
to  2805  f.  s. 

VVhiJe  we  were  going  backward,  the  Germans  were  going  to  the 
opposite  extreme.  During  the  first  World  War,  their  standard  infantry 
hullec  weighed  154  grains,  and  was  a flat  based  type,  with  a cone 
shaped  depression  in  the  base. 

For  machine  gun  use  during  that  war,  ihev  developed  a boat  tailed 
bullet  weighing  196  grains.  This  was  adopted  by  them  as  standard 
and  was  the  one  used  in  the  recent  war. 

In  our  own  Army,  the  tendency  is  definitely  to  use  armor  piercing 
ammunition  for  everything,  and  to  do  away  with  plain  ball.  The 
Armor  Piercing  Ammunition  that  we  use  now  is  nearly  identical  with 
rhiu  developed  immediately  after  World  War  I by  Co!.  Clay,  known 
as  the  M 1922.  Our  present  type  is  known  as  Cartridge,  Armor 
Piercing,  Caliber  .30,  M 2.  A black  tip  on  the  bullet  indicates  that  it 
is  armor  piercing.  The  bullet  weight  is  168.5  grains. 

Charactfriitfct  of  the  Various  Types 


.Muzzle  Inscrvi'  tnstru- 

Bullet  Velocity  mcnrskl  itjuntal  Muzzle 

weight  foot  velocity  velociy  Energy 

'Fype  grains,  seconds.  0 53  Ft.  0 78  ft.  Ft.  lbs. 

Cn\.  .3o**o6  I to  3700  i6fy  3640  3439  Ft.  lb. 

Cal.  .30  .M I ’74-5*  ^647  zdto  z6w  267s  Ft.  lb. 

Cal.  .30  .M2  152*  28of  2755  2740  2656  Ft.  lb. 

Cal.  .30  A-P.  Ms  ....  168.5*  *775  *75^  *7*5  *7^^  Ih* 


* Maxim  11m  weigiu  minlnkum  3 grains  less. 


H^TCHER’s  Notebook 


Tables  of  Fire 


Range, 

yards. 

Cal.  .30-06 
Angle  of 
Departure. 
Minutes. 

lOO 

2.6 

JOO 

^.2 

100 

8.5 

400 

1 1 17 

A j ly 

5CXJ 

15.B 

600 

20.7 

700 

26.3} 

Sqo 

32dl 

CWfl 

w* 

1000 

48.? 

I 

i 

.;o»  Mr 

Maximum 

Range 

Angle  of  eltT. 

Time  of  flight 

ordinate 

Angle  o£  fall 

Yards 

minutes 

seconds 

feet 

minutes 

roo 

*.? 

0.12 

4 * * 

*•7 

200 

o.?5 

0.} 

6.1 

300 

^-39 

0.6 

!0.1 

400 

11^ 

0.54 

r.17 

14.9 

500 

15-9 

0.70 

2.01 

20.23 

doo 

20.25 

oU 

>7-5 

700 

25.31 

1-07 

4.56 

35.B 

800 

30.7 

1.27 

46.2 

900 

1.50 

9.00 

959 

TOGO 

4}‘S 

1-75 

12.3 

?4'3 

Cartridge,  Bail,  Cel,  .50,  Mi 

Maximum 

Ranee 

Angle  of  dev. 

Time  of  flight 

ordinate 

Angle  of  fall 

Yards 

minutes 

seconds 

feet 

minutes 

100 

M 

0.12 

34 

200 

51 

0.25 

0.3 

6.8 

300 

K.i 

0.3K 

0.6 

lO.I 

400 

11.5 

0.5} 

1.2 

'3*5 

fOO 

0.70 

T.R 

20.3 

doo 

20.J 

o.^ 

3.0 

304 

700 

2^,0 

I.II 

5‘* 

40.5 

800 

3M 

>•55 

7-> 

574 

900 

40.2 

I4$2 

10.8 

74*3 

1000 

49*? 

I.91 

>5*5 

94-5 

A BlUiiF  iilSTOKY  OF  IH£  StUVlCE  CaR'I'KIDOKS 


3^ 


Cartridge,  Bail  Caliber  Armor  Piercing  Ma 


Range 

Yar3s 

Angle  of  dev. 
minutes 

Time  of  flight 
accQods 

Maximuin 

ordinate 

feet 

Angle  of  fall 
minutes 

200 

S' 

0.24 

0.J 

5*7 

400 

ti.5 

0.52 

1.2 

14.5 

(Vio 

t9uS 

ofly 

5-0 

29.7 

800 

30.7 

KJO 

6^ 

54-0 

1000 

46.2 

iJiz 

*3-5 

9U.1 

Table  of  fire  for  the  aa  CaHber  Long  Rifie  Cartridge 


Range, 

yards 

Velocity, 

f.s. 

Energy 
ft.  lbs. 

, Time  of 
flight  sec. 

Drop  at 

tawc. 

inches 

Mid  range 
ordinate 
inches 

Angle  of 
departure, 
minutes 

0 

1,(00 

102 

15 

1/570 

95 

04>68 

0.89 

0.24 

3*5 

50 

(,020 

39 

0.140 

5‘7 

0.98 

7’^ 

7S 

960 

84 

0.214 

8.06 

2.28 

117 

(00 

950 

79 

0.292 

4.08 

15. 8 

125 

920 

75 

O.J7» 

*4*73 

6.78 

20.5 

t;o 

890 

V 

®-455 

36.64 

(0.02 

24.9 

•75 

8do 

hj 

0.541 

50.80 

(4.20 

t9>6 

300 

840 

0.6)0 

7*-93 

(9.10 

34'3 

225 

8(0 

6f 

0.720 

93-H 

28.30 

39*7 

250 

79® 

53 

oil2 

ii8.ai 

J1.87 

44«7 

275 

77® 

55 

0.911 

147.20 

39.87 

50<8 

^00 

75® 

5* 

1.005 

177.12 

48.69 

55*7 

Table  of  Fire  for  the  Cariridge,  Bally  Cal,  4$ 

Deflection  due 

Tune  of  Flight 

to  drift,  inches 

Range,  Yards 

Seconds 

Drop,  Inches  (To  the  Left) 

(O 

0X))7 

0.5 

0,1 

20 

0.75 

i.i 

0.2 

5® 

0.II5 

*-4 

0.) 

4® 

0.151 

4-4 

04 

60 

0.229 

9-9 

0.8 

80 

0.308 

i84> 

J-3 

100 

0.388 

2845 

2.0 

Automatic  Gun  Mechanisms 


An  autonucic  firearm  is  one  which  fires,  throws  out  the  empty 
aircridgc,  and  reloads  itself  when  tlic  trigger  is  pulled.  Svrictly 
autoviAttc  firearms  will  also  keep  on  llring  as  long  as  the  trigger  is 
held  down;  but  the  term  auioinatic  pistol,  ur  automatic  shotgun,  etc., 
is  often  used  to  designate  what  is  more  properly  called  a s(i7niauto7natic 
or  self-loadi/jg  gun,  which  is  one  that  unloads  and  reloads  itself  but 
which  fires  only  one  shoe  for  each  pull  of  the  trigger.  Thus  ou  the 
Government  automatic  pistols  the  trigger  must  be  released  and  pulled 
again  for  each  shoe  fired. 

The  first  automatic  firearm  was  the  Maxim  machine  gun,  Machine 
guns  were  known  for  many  years  before  the  advent  of  the  Maxim 
gun  in  1884  but  these  older  machine  guns  were  hand-operated.  In 
other  words,  they  were  worked  with  a crank  like  a sausage  grinder, 
the  cartridges  being  fed  into  a hopper,  or  feed- way,  by  one  hand 
while  the  other  one  turned  the  crank.  In  1880  Sir  Hiram  Maxim 
constructed  a mechanism  in  which  the  barrel  of  the  gun  was  allowed 
CO  kick  back  for  about  chrec-rjnarters  of  an  inch  w'hen  the  shot  was 
fired,  and  rhi.s  liarkward  morion  was  ulili/«d  to  unlock  the  breech, 
eject  the  empty  cartridge  and  feed  a new  one  in.  Maxim's  gun  was, 
tnercfcirc,  vvliac  is  known  as  a reccfil^operatcd  gun. 

It  was  not  very  long  after  this  that  John  \f.  nn>\vning,  a gunsniith 
of  Ogden,  Leah,  conceived  the  idea  of  making  an  automatic  gun  that 
would  operate  like  a lirric  gas  engine.  He  bored  a hole  in  the  barrel  of 
the  gun  about  a fool  from  the  muzzle  and  fitted  this  hole  with  a 
piston  on  the  end  of  a .swinging  lever.  When  the  gun  was  fired,  the 
bullet  first  passed  this  little  hole  in  the  barrel,  then  the  gas  under  very 
high  pressure  struck  on  the  piston  resting  in  this  hole  and  drove  it 
downward  with  great  force.  This  piston  was  on  the  end  of  a lever 
which  was  swunc  downward  and  to  the  rear  by  the  force  of  the  gas, 
operating  a connecting  rod  which  worked  the  breech  mechanism. 
This  gun  was  said  to  be  gas~(^pcTtfted.  The  invention  of  the  Colt  gun 
by  Browning  in  1889,  was  almost  immediate!  v follov^ed  by  the  in- 
venrion  by  Baron  Von  Odkolek,  in  Austria,  of  a gun  in  which  the 
gas  acted  an  a piston  moving  straight  to  che  rear  in  a cube  under  the 
barrel.  This  gun,  also  gas^operated,  was  subsequently  developed  into 
the  Hotchkiss.  More  about  these  inventions  will  be  found  in  a later 
chapter. 

As  soon  as  the  first  successful  machine  gun  was  produced,  this  vci^^ 
fact  turned  the  attention  of  inventors  to  the  subject  of  automatic 


.'T 

> 

✓ 

\ ♦ ® 

iHkMinHiM«tmi« 

34 


Hatcher’s  N<itf.book 


firearms  and  aluiosc  immediately  there  were  a large  number  of  in- 
ventions produced  along  this  line.  Many  of  the  early  eiforts  turned  to 
pistols  and  some  successful  ones  Mich  as  the  Mauser,  Luger,  and  Colt, 
were  soon  produced.  All  these  guas  worked  on  the  recoil-operated 
principle. 

During  the  half  century  that  has  elapsed  since  the  automatic 
machine  guns  first  demonstrated  their  success,  there  have  been  hun- 
dreds of  attempts  to  make  machine  guns,  scmi-autoniacic  rifles  and 
automatic  pistols,  and  the  patent  offices  and  war  departments  of  the 
world  have  been  inundated  hv  a constant  flood  of  inventions  of  this 
general  category.  It  is  really  amazing  to  see  the  different  ingenious 
devices  that  were  thought  of  in  an  effort  to  produce  a successful 
semiautomatic  shoulder  rifle.  .Most  models  of  such  guns  were  either 
recoil-operated  or  gas-operated,  but  there  have  been  dozens  of  models 
ba'icd  on  novel  principles,  such  as  operation  by  the  movement  of  the 
primer  in  the  cartridge  case;  inertia-operated  shoulder  guns  in  which 
a sliding  weight  remains  relatively  stationary  while  the  gun  recoils; 
guns  with  movable  butt  plate  resting  on  the  shoulder  of  the  firer  and 
ope  ratine  through  a sysrein  of  rods  to  unlock  the  gun  when  the  kick 

Eiishcd  the  bnee  plate  against  the  fircr’s  shoulder;  guns  in  which  the 
reech  was  held  stationai^'  and  the  barrel  allowed  to  move  forward; 
and  itiany  others,  the  principal  ones  of  which  will  be  described  in 
detail  later. 

Much  of  the  mechanism  of  the  machine  gun  is  involved  in  the 
locking  and  unlocking  of  the  breech  block.  A high-powered  rifle 
cartridge  generates  a pressure  of  50.000  pounds  to  the  square  inch 
when  the  gun  is  fired,  and  this  pressure,  acting  on  rhe  head  of  the 
cartridge  ca.se,  tends  to  force  the  breech  block  to  die  rear,  Accord- 
ingly, when  high  pressure  cartridges  arc  used,  the  breech  block  must 
he  seciirclv  locked  ro  the  rear  end  of  the  barrel  in  order  co  hold  the 
cartridge  in  the  chairibcr  of  the  gun  during  the  explosion.  However, 
the  force  of  the  explosion  of  a cartridge  is  gone  in  a very  small 
fraction  of  a second.  The  high  pressure  of  50,000  pounds  to  the  square 
inch  lasts  less  chan  one-thousandth  of  a second  and  then  drops  rapidly 
off  to  zero. 

If  we  had  a fairly  heavy  breech  block,  it  would  not  move  enough 
to  do  any  harm  during  tfic  very  short  time  the  pressure  lasts.  If  the 
weight  of  the  brccch  block  could  be  chosen  correctly,  it  would  be 
possible  to  make  a breech  mechantsixi  in  which  no  locking  device 
would  be  necessary'-  The  pressure  on  the  cartridge  case  would  be 
just  sufficient  co  give  the  heavy  breech  block  enough  movement  so 
chat  the  breech  would  open  after  the  cartridge  is  fired,  and  if  the 
proper  spring  were  put  behind  the  breech  block  it  would  close  again, 
pusfiing  a new  cartridge  in  at  the  same  time. 


35 


Automatic  Gun  Mrchani&ms 
Blou'-back  Mf^cbanisnts 

Actually  this  type  of  breech  mechanism,  called  the  straif^ht  blo^w- 
back  system,  is  perfectly  practical  for  low-powered  cartridges,  and 
such  mechanisms  are  used  on  altnosc  all  pocket  automatic  pistols  and 
on  caliber  .22  pistols  and  rifles.  The  breech  block  is  simply  held 
against  the  heaa  of  the  cartridge  by  a spring,  and  when  the  gun  is 
fired,  the  powder  pressure  blows  the  bullet  om  through  the  inuzzlc 
with  very  great  rapidity,  and  at  the  same  time  pushes  the  breech 
block  back  with  just  the  right  speed  to  extract  the  fired  case  after 
(he  powder  pressure  has  fallen  to  zero.  If  the  breech  block  is  made 
too  light,  it  will  open  too  quickly,  and  if  it  opens  while  pressure 
is  still  in  the  cartridge  case,  the  cartridge  case  w’ill  be  ruptured  and 
gas  will  escape  co  the  rear. 

Calculations  and  experiments  have  shown  that  for  the  caliber  .30 
cartridge,  such  as  is  used  in  the  Sprii^lield  rifle,  the  hrcech  block 
would  have  to  weigh  in  the  neighborhood  of  twenty-seven  pounds  to 
operate  satisfactorily  on  the  blow-back  principle.  As  the  Springfield 
rifle  itself  weighs  only  nine  pounds,  the  use  of  this  kind  of  breech 
mechanism  is  obviously  impracticable  for  a semiautomacic  shoulder 
rifle  using  the  Springfield  cartridge,  where  the  weight  must  be  kept 
dnwn  to  rhe  lowest  possible  figure.  Moreover,  such  a breech  block  is 
entirely  coo  heavy  for  even  a machine  gun  using  the  full  powered 
Army  riile  cartridge. 

However,  straight  blow  back  guns  powerful  enough  for  hunting 
have  been  produced  but  these  guns  are  considerably  less  powerful 
than  the  Army  rifle.  The  most  powerful  hunting  rifle  built  on  the 
blow-back  principle  is  the  Winchester  self-loading  rifle  which  was 
made  in  .32,  .35,  .351  and  .40c  calibers,  with  a straight  cartridge 
shaped  somewhat  like  a large  pistol  cartridge. 

Even  though  the  mechanisms  of  the  blow'-back  type  do  not  seem 
CO  be  suited  for  military  machine  guns  or  semiautomatic  rifles,  the 
straight  blow-back  principle  was  appbed  to  the  Springfield  rifle  in 
the  production  of  the  Pedersen  device,  described  elsewhere  in  thii 
volume.  This  remarkable  weapon  was  an  automiuic  bolt  for  the 
Springfield  rifle,  enabling  the  rifle  to  be  converted  in  a few  seconds 
into  a semiautomatic  gun  capable  of  firing  forty  shots  w'ith  one  re- 
loading and  having  detachable  magazines  so  that  after  the  forty  shots 
were  fired  new  magazines  containing  fort)*  more  cartridges  could  be 

attached  almost  instantly. 

¥ 

The  application  of  the  blow-back  principle  to  the  military  rifle  in 
this  case  w'as  made  possible  by  the  fact  that  instead  of  using  the  full 
powered  military  cartridge,  the  device  used  a caliber  .30  pistol  car- 
tridge of  very  much  the  same  size  and  dimensions  as  the  cartridge  for 
the  caliber  .32  automatic  pocket  pistol  buc  considerably  more  power- 
ful. The  device  was  in  realitj^  nothing  more  or  less  than  an  automatic 


/ 1 I 


BEFORE  FIRING 


/ / I ^ 


AFTER  FIRING 


w 


Fig.  1.  Diagram  of  $(raigh(  bJow-badc  bf«ech  closure  principle  as  used  io  the  Wiodiesiei  selMoadlng  rifle. 


[IaTCHRR’s  NtJTEBOOK 


Al  i'Omatic  Gun  iMk<jiamsms 


37 

pistol  specially  shaped  so  that  it  could  be  attached  in  the  breech  of 
the  rifle  in  place  of  the  regular  bolt.  The  additional  power  of  the 
cartridge  was  taken  care  of  by  a weight  attached  to  the  breech  block 
of  the  device. 

Fig.  1 is  a diagram  sl^owing  the  principle  of  the  Winchester  self- 
loading  rifle,  the  most  powerful  blow-back  gun.  In  order  to  handle 
the  powerful  cartridge  used  in  this  rifle^  the  breech  block  must  have  a 
considerable  amount  of  weight,  which  is  provided  by  attaching  co  it  a 
large  bar  of  iron  which  lies  inside  the  hollow  wooden  foreann  under 
chc  barrel.  The  weight  of  this  large  piece  of  metal  lying  inside  the 
forearm  of  the  gun,  gives  a rather  curious  balance  to  these  self-loading 
rifles,  but  aside  from  this  they  arc  very  satisfactory  guns. 

Referring  to  Fig.  i,  is  Chc  breech  block  proper,  but  B,  C,  and  D 
are  all  une  piece  of  metal,  as  the  sliding  weight,  D,  lying  inside  the 
hollow  wooden  forearm  of  the  gun  is  connccicd  to  the  breech  block. 
B,  by  the  slotted  section,  C,  which  straddles  the  i Magazine  well  and 
the  hammer.  When  the  gun  is  fired  the  breech  block  slides  to  the  rear, 
ejecting  the  empty  cartridge  case  and  at  the  same  rime  compressinp 
the  return  spring  £.  This  return  spring  then  forces  the  breech  blocK 
forward  again,  feeding  in  a new  cartridge  from  the  magazine.  The 
rearward  motion  of  the  brccch  block  also  serves  to  force  the  hammer 
clown  into  rhe  cocked  position.  l*hc  straight  blow-back  guns  are  the 
simplest  of  all  auto  mane  firearm.^  as  regards  mechanism. 

Si/bffwhim  Guvs 

Siilunadiinc  guns  are  called  machine  p^ols  by  the  Germans.  They 
are  weapons  larger  chan  a pistol  and  smaller  than  a rifle,  intended  to 
be  fired  from  the  shoulder  or  with  two  hands  from  the  hip.  They 
u.se  high  powered  pistol  cartridges,  and  can  usually  be  fired  cither 
full  or  scnu-automatically. 

These  weapons  were  much  used  during  World  War  II,  and  there 
arc  numerous  types  in  existence.  They  have  one  thing  in  common, 
and  that  is  the  fact  they  arc  built  on  the  straight  blow-back  principle, 
with  no  locking  mechanism  for  the  breech,  an  exception  being  the 
early  model  Thompson  which  had  a retarding  wedge.  This  however 
was  removed  in  later  models. 


Ic  requires  little  or  no  ingenuity  or  engineering  ability  to  build  a 
submachine  gun,  and  rhe  existing  models  exhibit  so  few  design  fea- 
tures of  interest  that  not  much  space  will  be  given  to  them  in  this 
work. 


There  is  just  one  outlet  for  really  fine  eneineering  in  the  field  of 
submachine  guns,  and  chat  is  in  Amplifying  the  manufacturing  proc- 
esses as  was  done  by  Col.  Studler  in  the  U.  S.  M3  type. 


38 


Hatchu(’s  Notebook. 
^^BlonyFonvariP^  Aiechanisfm 


VVc  have  seen  above  that  some  method  must  be  provided  to  hold 
the  breech  block  against  the  barrel  when  the  gun  is  fired,  because 
otherwise  the  pressure  of  the  powder  gas  pushing  back  on  the  cart* 
ridge  case  would  drive  the  breech  block  back  away  from  the  barrel 
and  let  the  cartridge  out  while  the  explosion  was  going  on.  With  the 
blow-back  gun  the  brccch  block  is  allowed  to  move  in  rhis  manner, 
but  is  made  heavy  enough  so  that  the  movement  docs  not  occur  too 
quickly. 

Instead  of  allowing  the  breech  block  to  move  back,  ic  would  be 
quite  possible  to  attach  the  stock  and  all  die  frame-work  of  the  gun 
hiTiily  to  the  breech  block  and  then  allow  the  barrel  co  move  forward 
w hen  the  gun  is  fired. 

In  1917  an  inventor  appeared  at  Springfield  Armory  w'ich  a machine 
gun  made  to  fire  the  iCrag  army  cartridge,  having  the  framework 
of  the  gun  solidly  fixed  and  the  barrel  loosely  mounted  so  that  it 
could  move  forward  against  the  action  of  a spring  when  tlie  gun 
was  fired.  This  gun  operated,  but  it  was  necessary  to  grease  the  car- 
tridge case  to  prevent  the  front  part  of  the  case,  expanded  by  the 
pressure,  from  sticking  to  the  barrel  as  it  moved  forward. 

While  iiorhing  came  of  this  effort,  it  should  be  noted  that  several 
automatic  pistols,  notably  the  Schwarzlosc  and  a model  by  Von 
Mannlichcer  have  been  constructed  on  this  principle. 

Retarded  Blov;-l/ack  Mechauism 

We  have  mentioned  above  that  with  light  cartridges  giving  low 
pressure  it  is  quite  possible  co  use  what  Is  known  as  the  straight  blow'- 
hack  breech  mechanism,  which  depends  entirely  on  the  weight  of 
the  breech  block  to  keep  ic  from  opening  too  quickly.  Wc  also  stated 
chat  with  the  full  power  army  cartridge  rhe  breech  block  would  have 
to  weigh  about  twenty -seven  pounds  to  prevent  ic  from  opening  loo 
soon  if  we  depended  on  weight  alone. 

There  arc  other  things  chat  wc  can  depend  on  besides  weight  to 
retard  a blow-back  action.  In  a straight  blow-back  the  cartridge 
merely  pushes  the  breech  block  directly  co  the  rear  so  that  the  full 
thrust  is  exerted  in  the  direction  of  tihe  motion.  Instead  of  using 
extra  weight  to  slow  up  the  action,  we  can  slow  it  up  by  arranging 
so  that  the  thrust  is  working  at  a mechanical  disadvantage;  in  other 
words,  so  that  it  takes  more  push  to  produce  the  same  amount  of 
motion  or  the  same  push  to  produce  less  motion. 

If  wc  arrange  the  breech  block  like  the  piston  of  a gas  engine 
so  that  ic  is  attached  to  a crank  and  connecting  rod,  it  is  quite 
obvious  that  if  the  crank  and  connecting  rod  are  exactly  on  dead 
center  the  breech  block  will  be  prevented  from  moving,  and  all 
the  force  will  be  transmitted  to  the  crank  shaft.  If  the  gun  were 


Automatic  Guk  i\1echanisa<s 


39 


made  like  this  it  would  never  operate  at  all.  However,  if  it  is  made 
so  that  the  crank,  instead  of  being  on  dead  center,  is  just  slightly  to 
one  side  or  the  other  of  it,  then  most  of  the  thrust  of  the  breech  block 
will  be  transmitted  to  the  crank  shaft,  or  in  this  case,  the  pin  support- 
ing the  connecting  rod;  but  there  will  be  a certain  component  of  if 
that  will  tend  to  drive  the  crank  pin  around  in  a circle  just  as  the 
explosion  docs  in  the  cylinder  of  an  antomobile.  If  the  crank  is  al- 
most exactly  on  dead  center  when  the  explosion  starts,  so  little  of 
the  force  in  the  breech  block  is  directly  applicable  at  once  to  moving 
the  crank  away  from  dead  center  that  the  motion  is  retarded  suffi- 
ciently to  enable  the  explosion  to  be  lai^ely  completed  before  the 
breech  block  moves  away  far.  The  further  away  the  crank  goes  from 
dead  center,  however,  the  more  power  the  breech  block  has  to  accel- 
erate the  motion. 

The  Schwarzlosc  machine  gun  is  made  on  this  principle  of  the 
retarded  blow-back,  with  the  crank  and  connecting  rod  attached  to 
die  breech  block  as  described  above.  Iii  addition,  the  breech  block 
is  made  fairly  heavy  and  there  is  a very'  strong  spring  beliind  it. 
All  these  elements  combine  together  to  retard  the  motion  enough 
so  that  full  powered  military  cartridges  can  be  handled  successfully, 
though  the  brccch  is  not  actually  locked  to  the  barrel 

The  diagram  of  the  Schwarzlc^  machine  gun  (Fig.  2)  shows  how 
rhe  crank  and  connecting  rod  work. 

There  is  one  cjueer  thing,  however,  that  is  common  to  almost  all 
blow-back  and  retarded  biow-back  guns,  and  that  is  that  there  is  a 
tendency  ro  rupture  rhe  cartridges  unless  they  are  lubricated.  This  is 
because  the  moment  the  explosion  occurs  the  thin  front  end  of  the 
cartridge  case  swells  up  from  the  internal  pressure  and  tightly  grips 
the  walls  of  the  chamber.  Cartridge  cases  are  made  with  a strong 
solid  brass  head  and  a thick  wall  near  the  rear  end,  but  the  wall 
tapers  in  thickness  until  the  front  end  is  quite  thin  so  that  it  will 
expand  under  pressure  of  the  explosion  and  seal  the  chamber  against 
the  escape  of  gas  to  the  rear,  ^^^len  tlie  gun  is  fired  the  thin  front 
section  expands  as  intended  and  ti?hdy  grips  die  walls  of  the  chamber, 
while  the  thick  rear  portion  docs  not  expand  enough  to  produce 
serious  friction.  The  same  pressure  that  operates  to  expand  the  walls 
of  the  case  laterally,  also  pushes  back  with  the  force  of  fifty  thou- 
sand pounds  to  the  square  inch  on  the  head  of  the  cartridge,  and  the 
whole  cartridge  being  made  of  elasdc  brass  stretches  to  the  rear  and, 
in  effect,  gives  the  breech  block  a sharp  blow  which  starts  it  back- 
ward. The  front  end  of  the  cartridge  being  lightly  held  by  the 
friction  against  rhe  walls  of  the  chamber,  and  rhe  rear  end  being  free 
to  move  back  in  this  maimer  under  the  internal  pressure,  either  one 
of  two  things  will  happen.  In  the  first  case,  the  breecli  block  and  the 
head  of  the  cartridge  may  continue  to  move  back,  tearing  the  car- 
tridge in  two  and  leaving  the  front  end  rightly  stuck  in  the  chamber; 


40 


Hai*cher’s  N(ti  >:b€)ok 


MAIN  SPRING 


BREECH  BLOCK 


POSITION  OF  PARTS  AT  INSTANT  OF  FIRING 


SEAR^ 
FIRING  PIN 


CONNECTINO  ROD 


CRANK 


BREECH  CLOSED  READY  TO  FIRE 


Figure  2,  Diagram  of  the  retarded  blow-back  closure  priacipic  as  used  ia 
the  Schwarziose  machiae  guo. 


Automatic  Gun  Mechanisms 


4» 

or,  if  the  breech  block  is  sufficiently  retarded  so  chat  it  docs  not 
allow  a very  violent  backward  modon,  the  result  may  simply  be  that 
the  breech  block  moves  back  a short  distance  and  the  jerk  of  the 
extractor  on  the  cartridge  case  stops  ic,  and  the  gun  will  not  operate. 

However,  this  difficulty  can  be  overcome  entirely  by  lubricating 
the  cartridges  in  some  way.  In  the  SchwatrJose  machine  gun  there  is 
a little  pump  installed  in  the  mechanisin  which  squirts  a single  drop 
of  oil  into  the  chamber  each  time  the  breech  block  goes  back.  In 
the  Thompson  Auto -Rifle  there  arc  oU-soaked  pads  in  the  magazine 
which  contains  the  cartridge.  In  the  Pedersen  semiautomatic  rifle  the 
lubrication  is  taken  care  of  by  coating  the  cartridge  with  a light  film 
of  wax. 


Pedersen  Semiautennatic  Rifle 

About  the  year  19:7  Mr.  J.  D.  Pedersen  perfected  a semiautomatic 
rifle  on  the  retarded  blow-back  principle,  which  rifle  gave  an  especially 
satisfactory’  account  of  itself  in  trials.  It  also  has  a crank  and  con- 
necting rod  as  does  the  Schwandose  gun,  but  the  mechanical  arrange* 
menc  is  somewhat  different.  The  operation  of  the  Pedersen  rifle 
is  shown  in  Fig,  3,  A is  the  breech  block  which  is  held  against 
the  head  of  the  cartridge  by  the  blocks  B and  G which  are  in 
line  with  each  other  and  which  transmit  the  thrust  of  the  breech 
block  to  the  heavy  pin,  £1,  which  goes  through  the  receiver.  These 
three  parts,  D and  G,  form  a toggle  joint,  and  C>  the  point  of 
contact  between  B and  G,  is  just  slightly  above  the  line  of  thrust 
between  the  head  of  the  canridge  case  and  the  pin,  D.  Thus  when 
there  is  a very  heavy  pressure  on  the  front  end  of  the  breech  block, 
/4,  there  is  tendency  for  the  tingle  joint  to  ‘^break*’  and  the  piece, 
B-G,  to  move  upward  as  shown  in  the  cut  marked  “After  Firing.” 
If  the  point  of  contact  at  C were  directly  on  the  line  of  thrust,  the 
toggle  joint  would  remain  locked  and  the  breech  would  not  open,  but 
as  this  point,  C,  is  just  above  the  line  of  thrust  the  breech  does  fly 
open  as  soon  as  the  pressure  comes  on  the  head  of  the  bolt,  but  this 
opening  is  retarded  because  the  two  pieces,  B— G,  roll  on  each  other 
in  starring  to  open  in  such  a manner  that  rhe  contact  point,  C,  con- 
tinues for  some  little  time  to  remain  near  the  line  of  dirust  The  shape 
of  the  rolling  surface  is  worked  out  very  skillfully  in  order  to  insure 
this  result.  As  the  breech  opens  the  spring,  F,  is  compressed  and  as 
soon  as  the  motion  is  completed  this  spring  causes  the  breech  to 
close  again. 

However,  like  the  'Fhompson  gun,  this  mechanism  starts  co  open 
while  the  high  pressure  is  still  on,  and  therefore  it  was  necessary  co 
lubricate  the  cartridges.  Instead  of  lubricating  them  with  oil,  each 
cartridge  was  coated  with  a very  thin  film  of  hard  wax  which  had 
a very  high  melting  point,  so  tliac  the  cartridges  w'ould  not  pick 
up  dirt  when  dropped  as  they  would  if  oily  or  greasy. 


4^ 


BEFORE  FIRING 


AFTER  FIRING 


Figure  3.  Diagram  of  retarded  bk>w>back  breech  closure  principle  as  used  in 
the  Pedersen  semiaucomactc  rifle. 


Hatcher’s  Notebook 


Automatic  Gun  Mechanisms  43 

There  was  a good  deal  of  talk  about  die  disadvantage  of  “Inbrica- 
rion”  in  this  gun;  but  after  all,  it  seems  chat  this  disadvantage  is 
more  fancied  than  real,  as  the  cartridges  arc  not  greasy  or  oily. 
Moreover,  it  lias  been  found  that  corrosion  is  one  of  the  greatest 
causes  of  season  cracking  in  brass  cartridge  shells,  and  if  this  wax 
prevents  the  cartridge  brass  from  corroding  it  may  be  quite  possible 
that  it  would  eliminate  dcreriiiration  of  cartridges  from  season 
cracking. 


Pedc^nen  .^*^6  curcrid^cs  in  hi«  len  shot  '"en  block*'  clip  designed  by  him  for 
his  semiautomatic  rifle.  U.  S.  cal.  .30  clip  for  cumparison 


Up  to  that  time,  all  the  semi-automatic  rifles  submitted  for  test 
had  been  required  to  be  of  .30  caliber,  adapted  to  use  the  service 
cartridge.  Mr.  Pedersen  presented  very  convincing  arguments  to 
the  effect  chat  the  .30  caliber  cartridge  was  more  powerful  chan 
was  required  for  the  shoulder  rifle,  and  that  to  reduce  the  caliber 
to  the  ballistically  ideal  7 inin  or  .276  would  result  in  a number  of 
advantages,  to  wit;  saving  in  weight;  saving  in  material,  reduction 
of  heating  in  rapid  fire:  ability  of  the  soldier  to  have  a larger  number 
of  cartridges  available;  etc. 

The  Army  made  an  extended  study  of  this  question,  including  a 
series  of  firings  at  live  animals  with  .256,  .276,  and  .30  caliber  bullets. 
It  was  found  that  the  .256  was  apparently  the  worst  killer,  on 
account  of  the  fact  that  the  bullet  had  less  diameter,  hence  less 


44 


Hatcher’s  Notebooic 


gyros tatic  stability,  and  would  yaw  badly  upon  impact,  and  make 
very  lethal  woulds.  The  .276  was  found  to  be  about  as  effective, 
and  as  k had  certain  advant^es  over  the  .256,  its  adoption  was  de- 
cided on  for  the  new  semi-automatic  rifle  that  it  was  hoped  would 
soon  be  adopted. 

The  cartridge  selected  liad  been  designed  by  Mr.  Pedersen  with 
features  making  it  especially  suitable  for  autoiiiadc  firearms,  such  as  an 
increased  taper  for  easy  extraction.  I'he  ammunition  was  first  made 
with  a solid  bronze  buhet  weighing  125  grains;  later  with  a 126  grain 
jacketed  boat  tail  bullet.  The  bullet  diameter  was  .2845.  The  charge 
was  about  30  grains  of  duPont  IMR  No.  25.  At  one  time  a small 
lot  of  this  ammunition  was  made  with  flat  base  bullets. 

The  Pedersen  gun  was  made  with  what  is  called  the  block  clip* 
This  is  an  arrangement  whereby  a packet  of  ten  cartridges  is  shoved 
bodily  into  the  magazine,  clip  and  all.  After  firkig  ten  shots,  the 
dip  a uco  Ilia  dually  jumps  out  of  the  rifle  and  the  bolt  stays  open, 
ready  for  the  next  clip  to  be  inserted. 

After  the  Pedersen  rifle,  using  the  special  .276  caliber  cartridge 
designed  by  Mr.  Pedersen,  had  successfully  passed  the  severe  Army 
tests,  it  seemed  on  the  point  of  adoption  by  our  armed  forces; 
but  a high  command  decision  was  made  not  to  change  the  caliber 
of  the  service  cartridge,  and  the  final  action  to  adopt  this  gun  was 
never  taken. 

Blhb  PrincipU 

Some  experiments  by  Commander  Blish,  U.  S.  Nav^%  retired,  led 
him  to  believe  that  inclined  surfaces  which  would  slide  on  each  other 
under  bghc  pressure  w'ould  not  slide  w'hen  the  pressure  was  heavier. 
He  is  said  to  have  been  started  on  this  investigation  through  observ- 
ing that  when  heavy  naval  guns  were  fired  with  full  charges  the 
breech  remained  locked,  whereas  when  they  w'erc  fired  with  light 
charges  the  breech  had  a tendency  to  unscrew  by  itself.  Accordingly 
he  took  out  U.  S.  Patent  No.  1,131,319,  dated  March  9,  1915,  cover- 
ing the  application  of  this  principle  to  firearms  and  describing  his 
findings  in  detail  with  elaborate  diagrams. 

Utilizing  this  theory,  the  Thompson  Autorifle  is  constructed  so 
that  the  breech  block  is  locked  to  the  barrel  by  a steep  thread,  The 
pitch  of  this  thread  is  made  just  steep  enough  so  that  the  gun  will 
not  unlock  too  quickly  under  the  full  pressure  of  the  explosion.  The 
supposition  is  that  while  the  fuU  pressure  is  on  the  breech  block, 
adhesion  of  the  threads  on  the  breech  block  to  the  threads  in  the 
receiver  will  prevent  anv  motion,  but  as  soon  as  the  pressure  drops 
slightly  this  adhesion  will  no  longer  operate  and  the  threads  will  then 
unscrew,  allowing  the  breech  block  to  open. 

A diagram  of  this  breech  closure  is  shown  in  Fig.  4.  The  breech 
block,  By  has  steep  threads,  D,  engaging  the  receiver,  C.  When  the 


Figufe  4.  Diagram  oi  the  Blisb  type  breech  closure  principle  u used  in  the  ‘niompson  Autorife. 


4^ 


Automatic  Gun  Mechanisms 


Hatcher’s  Notebook. 


46 

gun  is  fired  the  breech  block  unscrews  from  the  pressure  and  opens 
against  the  action  of  the  return  spring  w'hich  immediately  shuts  the 
breech  block  again  and  caases  it  to  rotate  into  the  locked  position 
when  the  threads  engage  each  other.  The  locking  of  the  breech  block 
is  assisted  by  the  action  of  a knob  on  the  end  of  the  bolt  handle 
which  adds  a sort  of  flywheel  effect  to  the  motion  of  the  bolt  and 
thus  assists  in  locking  it  securely. 

There  is  no  doubt  that  this  mecthanism  can  be  made  to  operate  as 
described,  provided  the  cartridges  are  lubricated,  but  there  has  been 
some  dispute  among  engineers  as  to  whether  or  not  the  Blish  principle 
really  exists.  Some  of  them  claim  that  this  is  merely  a retarded  blow- 
back  breech  mechanism  and  that  as  soon  as  the  pressure  comes  on  the 
end  of  the  holt  it  starts  to  unscrew;  but  on  account  of  the  fact  that 
the  angle  of  the  thread  is  so  slow  it  takes  a great  deal  of  pressure  to 
unscrew  it,  and  for  this  reason  the  bullet  is  gone  before  the  bolt  has 
unscrewed  enough  to  do  any  damage.  That  this  type  of  mechanism 
actually  opens  while  there  is  still  considerable  pressure  in  the  cartridge 
case  is  evident  from  the  fact  that  the  gun  docs  nor  operate  satis- 
factorily unless  the  cartridges  arc  lubricated. 

Thompson  Sub-Machine  Gun 

I’hc  'Ihompson  siib-machine  cun,  utilized  ro  fire  pistol  cartridges 
at  a rapid  rate  frcim  magazines  holding  20,  30,  50  or  roo  cartridges,  was 
also  constructed  hr  rhe  Blish  theory,  but  instead  of  having  a screwed 
breech  block  with  n steep  thread  as  docs  the  Thompson  Auto-rifle, 
ic  simply  has  the  breech  resting  against  a vertical  .sliding  wedge  held 
in  its  upper  position  by  spring  pressure.  When  the  breech  block 
is  pushed  backward  a sloping  surface  on  the  rear  end  of  the  breech 
block  resting  on  a sinitlar  surface  of  the  wedge,  cams  the  wedge 
downward  as  the  breech  block  moves  to  the  rear.  This  downward 
motion  nf  the  sliding  wedge  is  supposed  to  retard  the  breech  block 
in  its  rearward  motion  and  thus  ajwist  in  reliable  functioning.  Owing 
to  the  low'  pressure  involved  in  the  pistol  cartridge,  it  is  not  neces- 
sary to  lubricate  the  case. 

Recoil  Operated  Guns 

It  has  already  been  mentioned  that  the  first  machine  gun,  the 
Maxim,  was  recoil- opera  ted,  and  that  the  barrel  moved  back  about 
three-quarters  of  an  inch.  A gnu  in  which  the  barrel  moves  only 
a short  distance  and  the  breech  block  moves  through  the  rest  of 
its  travel  from  the  momentum  imparted  to  it  by  this  motion  of  the 
barrel,  is  called  a “short-recoil”  gun. 

There  is  another  kind  in  which  the  barrel  moves  all  the  w'ay  to 
the  rear  along  with  the  breech  block  and  then  leaves  the  breech 
block  back  in  the  rearward  position  while  the  barrel  goes  forward ► 
This  is  c<alled  the  “long-recoil”  type. 


Automatic  Gun  MiiCtiANiSAib 


47 

Both  of  these  u'ill  be  described  in  tuni,  and  as  the  simplest  example 
of  the  short-recoil  type  of  action  we  will  take  the  Service  automatic 
pistol  shown  in  Fig.  5. 

Colt  Automatic  Pistol 

In  this  mechanism  the  barrel  and  breech  arc  locked  together,  and 
when  the  gun  is  fired  the  recoil  drives  them  both  back  at  one 
rime.  However,  it  takes  only  about  one-<piarter  of  an  inch  of  motion 
r<>  unlock  the  breech  block  from  the  barrel  and  as  soon  as  this 
one-qiiartcr  inch  has  been  completed,  the  barrel  strikes  sharply  against 
a stop  ami  rcm.iins  in  position  while  the  breech  block  continues  on 
back  through  the  momemum  imparted  to  it  by  the  onc-t]uartcr  inch 
kick,  coupled  with  a residual  pressure  that  m.iv  remain  in  the  ease. 

The  action  in  detail  is  as  follows:  (Refer  to  Fig.  5) 

Referring  to  the  diagram  marked  ^‘Before  Firing”  it  will  be  ob- 
served that  the  barrel,  /4,  is  locked  to  the  slide,  li  (which  is  in  one 
piece  with  the  breech  block),  by  the  locking  dioulder,  C,  formed  on 
top  of  the  barrel  and  fitting  into  the  recesses,  D,  in  the  slide.  When 
the  gun  is  fired  the  recoil  pushes  the  slide  and  breech  block,  B,  to 
ihe  rear  and  as  rhe  slide  is  locked  to  the  barrel,  the  barrel  is  also 
carried  to  the  rear.  However,  the  barrel  is  pivoted  to  the  frame  of 
the  pistol  by  means  of  the  link,  E,  and  as  the  barrel  continues  its 
rearward  motion,  the  top  end  of  this  link  first  moves  backward  in 
rhe  arc  of  a circle  and  then  downward  around  the  lower  pin  as  an 
axis.  I'his  motion  swings  the  back  end  of  the  barrel  downward,  and 
disengages  the  locking  shoulders  in  the  slide,  which  cnntimics  to 
the  rear,  leaving  the  barrel  in  position  with  irs  bottom  lug  against 
the  scop  shoulder  in  the  frame.  This  rcaruMrd  motion  of  the  slide 
throws  out  the  empty  cartridge  and  at  the  same  time  compresses  the 
reaini  spring,  which  immediately  returns  the  slide  to  its  fonvard 
position,  at  rhe  same  rime  feeding  a new  cartridge  into  the  chamber 
from  the  rnagarinc  in  the  handle  (not  sliown  in  the  drawling).  As 
rhe  slide  complectts  its  forward  motion,  it  strikes  against  the  rear  end 
of  the  barrel  and  as  the  barrel  goes  forward  ir  swings  upward 
through  the  action  of  the  link,  causing  the  locking  shoulders,  C,  to 
engage  in  the  recesses,  D,  in  the  slide. 

Maxhft  and  Brcnvnhts  Machhie  Guns 

These  two  guns  are  also  examples  of  the  short-recoil  type  of 
mechanism,  but  in  a much  more  refined  fonn.  As  described  above 
for  the  Coir  pistol,  the  barrel  goes  back  about  one-c^uartcr  of  an 
ineb  carrying  the  breech  block  with  it  and  stops  with  a bang  against 
the  solid  shoulder  and  lets  the  breech  block  go  on  to  the  rear  bv 
its  own  momentum.  This  will  work  Avith  a low-powered  cartridge 
like  chat  used  in  the  pistol,  but  even  so  the  shock  to  the  action  of 


00 


J‘igur«  5.  of  ihe  shori*recoil  lypc  brcerh  closure  principle  as  used  in  the  Colt  automatic  pistol. 


Hatcher's  Notkiiook 


Automatic  Gun  Mechanis»ms 


49 


full  I fhUrt  r 

TOP  VIEW  8M0WINC  RECAT)ON  OT 
POLLE  R HAN  DLE  ANO  RECCE.  SmNG 


RI6HT  SlOCOr  REC&VCR  SHOWING  ACTION  cr  ROLLER  HANDU 


^ I II  ■ HI  HI 


‘TIWliPWWw 
/ 


kCW  tfnf  MCTOM 

CNO  or  RECOIL 


END  or  RECOIL 


UCH  ra«i 
M/t**  HA*  »MIH« 

e«M<H 


CROSS  SECTION  T»m  LOCK 
SHOWMC  riRMC  I^CHANISM 


Figure  6.  DiagrEtn  of  the  ^ori'TctoiJ  type  breech  do$ure  principle  as  used 
ia  thi  Maxim  maebioe  gun. 


the  gun  is  severe,  and  with  a high  powered  cartridge  it  is  necessary 
CO  resort  to  some  device  by  which  the  barrel  is  gradually  brought 
Co  a stop  through  transferring  its  energy  to  the  breech  block  and 
then  allowing  it  to  be  gradually  absorbed  through  a fairly  long 
travel  of  the  hrccch  blfK:k  against  the  return  spring. 

In  the  Maxim  machine  gun  (Fig.  6)  the  locking  of  the  breech 
is  accomplished  by  having  the  breech  block  (called  in  this  gun  the 
“lock”)  attached  to  the  barrel  extension  (called  in  this  gun  the 
“recoil  places”)  through  the  medium  of  a crank  and  connecting  rod 


Hatcher's  Notebook. 


5c» 

(called  in  this  gun  the  *'slidc  lever”)  as  was  discussed  under  the 
subject  of  retarded  blow-back  guns.  However^  in  the  Maxim  gun  the 
crank  is  on  dead  center  when  the  explosion  comes,  so  that  the  lock 
cannot  move  back  in  relation  to  the  barrel,  and  the  thrust  of  the 
cartridge  on  the  lock  is  transmitted  through  the  side  lever  and  crank 
to  the  crank  axle  and  thence  to  the  recoil  places  through  which  the 
crank  axle  passes.  Hence  the  barrel,  lock  and  recoil  plates  all  move 
back  together  as  a unit,  under  the  force  of  the  recoil. 

On  the  right-hand  end  of  the  crank  axle  is  a handle  with  a convex 
shaped  bottom,  and  this  handle  rests  on  a roller  attached  to  the 
.side  of  the  gun.  As  the  barrel,  lock  and  recoil  plates  move  hack 
together,  this  handle,  which  is  on  the  axis  of  the  crank,  also  moves 
back,  while  the  roller  is  iixed  in  position  on  the  side  of  the  gun. 
An  examination  of  the  figure  will  readily  show  that  this  backward 
motion  of  the  roller  handle  against  the  roller  causes  it  to  rotate  so 
chat  the  back  end  of  the  handle  moves  upward.  This  rotation  of  the 
crank  axle  by  means  of  the  roller  handle  throws  the  crank  and  con- 
necting lever  off  dead  center  and  draws  the  lock  away  from  the 
barrel.  In  ocher  words,  as  soon  as  the  roller  encounters  the  cam  on 
the  roller  handle,  the  action  of  the  cam  i.s  to  slow  down  the  barrel 
ami  rran.sfer  its  motion  into  an  accelerated  rearward  morion  of  the 
breech  block.  Mowevei*,  as  the  rotation  of  the  roller  handle  coii- 
Unue.s  the  tail  of  tlie  roller  handle  strikes  on  the  roller  and  by  the 
action  of  these  two  surfaces  on  each  other  the  rotation  of  the  roller 
handle  is  checked  and  the  recoil  plates  are  pushed  forward,  shoving 
die  barrel  to  battery. 

On  the  left-hand  side  of  the  gun  there  is  a strong  spring  attached 
CO  the  extension  on  the  end  of  the  crank  axle.  This  recoil  spring 
tends  to  do  two  things;  first,  to  keep  the  barrel  puUed  into  battery  and 
resist  any  rearward  motion,  and  second,  to  keep  the  roller  handle 
rotated  so  that  the  lock  in  the  clased  posirinn.  As  soon,  therefore, 
as  the  barrel  has  been  returned  to  batter v bv  the  reaction  of  the  tail 
of  the  roller  handle  against  the  roller,  assisted'  by  the  pull  of  the  recoil 
spring,  a further  pull  of  the  spring  rotates  the  handle  back  into  the 
original  position,  and  closes  the  breech  of  the  gun,  putting  the  lock 
back  in  the  firing  position.  This  action  can  be  very  easily  understood 
from  the  diagrams. 

However,  the  drawing  does  not  show  the  method  of  feeding  the 
cartridges  into  the  gun.  They  are  supplied  in  a fabric  belt  and  there 
is  a feed  crank  operated  bv  the  recoil  of  the  barrel  which  advances 
a fresh  cartridge  into  position  each  time  the  barrel  move.s  to  the  rear. 

The  Browning  gun  accomplishes  the  sajne  thing  in  a somewhat 
d liferent  manner.  In  this  gun  the  barrel  moves  to  the  rear  about 
five-eighths  of  an  inch.  There  is  a frame  screwed  onto  the  back  end 
of  the  barrel.  This  frame  is  called  the  barrel  extension,  and  the  heavy 
breech  bolt  is  locked  to  this  frame  dirough  the  medium  of  a 


t 


f c 0 5 


BEFORE  FIRING 


CD  » 


END  OF  RECOIL 


ngure  7.  DUgram  of  short  recoil  type  breed)  closure  priociple  used  in  ihe  Browning  machine  gun. 


Automatic  Gun  Mechanisms 


Haicher’s  Notebook 


5* 

vertical  sliding  bole,  calkd  [he  brecdi  hK*k,  which  is  actuated  by  a 
cam  on  the  boccon*  of  xi\c  gun.  Tims  when  rhe  barrel  and  barrel 
extension  arc  in  the  forward  position,  the  holt  is  locked  securely  to 
the  barret  extension.  However,  when  tite  barrel  recoils  abour  one- 
half  iiich  the  breech  lock  cam  is  drawn  down  out  of  engagement  with 
the  bolt  and  the  bolt  is  entirely  free  from  the  barrel  and  barrel  exten- 
sion. As  the  barrel  condnxtcs  ks  backward  motion  it  strikes  acrainst  die 
convex  side  of  a curved  lever,  the  point  of  which  rests  against  the 
breech  block.  The  continued  motion  of  the  barrel  tu  the  rear  swings 
this  lever  backward  in  such  a manner  as  to  separate  the  breech  block 
from  the  barrel;  in  other  words,  to  slow  up  the  barrel  and  speed  up 
the  breech  block,  throwing  ii  forcibly  from  the  barrel  and  at  the 
same  time  extracting  the  cartridge  case.  Of  course  the  breech  block 
already  had  a rearward  motion  imparted  to  it  w'hile  the  barrel  was 
recoiling,  but  rlik  motion  is  increased  or  accelerated  by  the  action  of 
the  curved  lever  which  is  accordingly  called  an  accelerator. 

Tlic  mechanism  of  this  gun,  which  is  shown  in  Fig.  7,  will  n*i\v 
be  described  in  detail.  The  barrel,  Ay  is  screwed  into  the  barrel  c.v- 
cension,  S.  which  extends  to  the  rear  for  several  inches  and  carries  in 
a slot  in  its  rear  end  the  vertical  sliding  breech  lock,  C.  In  the  dosed 
position  the  breech  lock  cam.  I),  in  the  bottom  of  the  gun.  holds  the 
breech  lock  up  so  that  its  top  end  engages  in  a slot  in  the  holt, 
and  locks  it  to  the  barrel  extension. 

When  the  gun  is  fired,  the  barrel,  Ay  recoils  about  five  eighths  of  an 
inch  carrying  with  it  the  barrel  extension,  B,  the  breech  lock,  C,  and 
the  breech  bolt,  £,  all  locked  togeiher.  However,  as  the  parts  move 
to  [he  rear  the  breech  lock  moves  off  the  high  surface  on  the  breech 
lock  cam  and  a transverse  pin  through  the  breech  lock  strikes  a slant- 
ing surface  on  the  lock  frame,  G,  which  forces  the  breech  lock 
down  out  of  engagement  with  the  breech  block. 

Just  under  the  breech  bole  there  is  an  accelerator,  F,  pivoted 
on  a horizontal  axk.  As  the  barrel  extension,  B,  moves  to  the  rear  it 
swings  this  accelerator  backward  and  the  point  of  the  accelerator 
catches  in  a notch  in  die  bolt  and  throws  the  bolt  forcibly  to  the  rear, 
compressing  the  return  spring  which  immediately  returns  the  bolt 
to  its  forward  position. 

While  the  bolt  is  in  the  rearward  position,  the  barrel  extension  and 
lock  frame  are  fasreiicd  together  by  the  accelerator  in  such  a position 
chat  the  barrel  cannot  move  forward.  However,  when  the  bolt  goes 
fonvard  far  enough  to  strike  the  accelerator,  it  disengages  Che  barrel 
extension  from  the  lock  frame  and  allows  the  barrel  and  barrel  ex- 
tension to  move  forward  with  the  bolt  as  it  completes  its  motion. 
The  forward  motion  of  the  barrel  extension  carries  along  with  it  the 
breech  lock  which  rides  up  the  sloped  siirfrce  of  the  breech  Jock 
cam  and  again  locks  the  bolt  to  the  extension  ready  for  firing. 

The  backward  motion  of  the  bolt  extracts  the  empty  cartridge 


Automatic  Gun  Msx:iianisms 


53 

case  and  che  forward  motion  feeds  a new  one  in.  The  top  of  the  bolt 
has  a cam  slot  in  it  which  actuates  the  lever  which  feeds  tlie  belt 
of  cartridges  in,  che  width  of  one  cartridge  each  rime  the  bolt  moves 
to  the  rear. 

Limg’RecoH  Type 

I'hc  long-recoil  t^pc  of  automatic  mechanism,  in  which  the  barrel 
and  breech  hole,  locked  together,  recoil  for  several  inches,  and  then 
che  breech  holt  is  held  back  while  the  barrel  goes  forward,  is  used 
for  the  Remington  auto-loading  rifle,  the  Remington,  VVuichcsrer 
and  llrowning  automatic  shotguns,  and  the  Chauchac  machine  rifle. 

In  a typical  gun  of  this  type  there  are  two  return  springs,  one  to 
return  the  barrel  and  a separate  one  to  return  the  breech  block.  The 
breech  block  being  locked  to  the  barrel  when  the  cartridge  is  flied, 
the  pressure  on  the  head  of  the  breech  block  drives  it  three  or  four 
inches  eu  the  rear  until  it  is  arrested  by  striking  a scop  provided  for 
this  purpose.  The  barrel  being  locked  to  che  breech  block,  also  goes 
to  the  rear  and  this  rearward  motion  compiesscs  both  the  breech 
block  return  spring  and  the  barrel  return  .spring.  When  the  breech 
block  has  reached  che  limit  of  its  rearward  motion,  it  is  caught  and 
held  in  chat  position  by  a latch.  The  barrel  return  spring  then  pushes 
the  barrel  forward  and  che  lock  on  che  breech  block  is  so  constructed 
that  when  the  breech  block  is  held  and  the  barrel  is  pulled  forward, 
the  bolt  will  unlock  itself  from  the  barrel  and  allow  me  barrel  to  go 
forward.  A.s  the  barrel  goes  forward,  che  empty  cartridge,  held  to 
the  hrecch  block  by  the  extractor,  is  ejected.  As  the  barrel  reaches  its 
forward  po.sieion,  it  strikes  a lever  which  drops  the  latch  and  allows 
the  brcedi  block  to  come  forward,  feeding  m a new  cartridge. 

Remington  Auto^Loading  Rifle 

The  action  of  this  type  of  breech  closure  can  be  followed  in  detail 
by  rcferencx  to  Fig.  8 showing  the  Remington  auto-loading  rifle. 
The  barrel,  A,  is  stipported  in  a barrel  jacket,  B,  and  is  held  forward 
by  the  coil  spring,  /,  surrounding  the  barrel.  The  breech  block,  £, 
has  a turning  bolt  head,  D,  arranged  to  be  rotated  by  the  action  of 
two  pins,  t\  u'orking  in  cam  slots  cut  in  the  sides  of  the  bolt  head,  1). 

I'his  bole  head  is  arranged  to  lock  in  che  barrel  extension,  D,  by 
che  action  of  che  pins,  F,  in  the  cam  slots,  turning  the  bolt  head. 
There  is  a separate  return  spring,  G,  for  holding  che  breech  block  in 
the  forward  position. 

When  the  gun  is  fired,  the  parts  recoil  into  the  extreme  rearward 
position,  as  show  n in  the  figure  marked  “End  of  Recoil/’  Ac  this  point 
che  breech  block  is  locked  in  its  rearward  position  by  the  latch,  H, 
and  che  barrel  then  starts  forward  under  the  impulse  of  the  barrel 
return  spring,  I.  As  che  barrel  moves  forward  it  draws  with  it  the  bolt 
head,  Df  but  this  forward  motion  of  the  bolt  head  causes  the  pins,  F, 


BEFORE  FIRING 


END  OF  RECOIL 


END  OF  COUNTER  RECOIL 


figure  8.  Diagram  of  the  long-recoil  type 


closure  priodple  as  used  in  the  Remington  autoloading  rifle. 


Hatcher’s  Notfbook 


Automatic  Gun  Mechanisms 


55 

to  act  in  the  cam  slots  so  as  to  rum  the  bok  head  and  release  it  en- 
tirely from  the  barrel.  As  the  barrel  continues  forward  it  leaves  tfie 
empty  cartridge  case  held  by  the  extractor  and  when  the  barrel  is 
entirely  off  the  cartridge  case  a spring  ejector  in  the  bolt  head  kicks 
the  cartridge  out  of  the  gun.  At  this  moment  the  parts  have  reached 
the  position  marked  “End  of  Counter-recoil’*  and  the  curved  surface 
on  the  bottom  of  the  barrel  at  the  rear  end  strikes  against  the  lever, 
X,  which  in  turn  disengages  tfic  latch,  Hy  allowing  the  breech  block 
to  be  pushed  forward  again  by  the  spring,  G.  As  the  breech  block 
goes  forward  it  feeds  a new  cartridge  ituo  the  barrel  from  the 
magazine  (not  shown).  As  the  bolt  approaches  its  forward  position, 
the  bolt  head,  D,  enters  the  recess,  C,  in  the  barrel  and  then  a further 
motion  of  the  bolt  causes  the  pins,  F,  to  act  on  the  cam  slots  in  the 
bolt  head  in  such  manner  as  to  turn  the  bolt  head  and  loclc  it  to  the 
barrel  so  that  the  gun  is  again  ready  for  firing. 

GaS’OperareJ  Type 

While  the  original  machine  gun  was  built  on  the  recoil-operated 
principle  and  while  nearly  all  automatic  pistols  arc  made  on  that 
principle,  the  gas-operatC(l  system  has  also  been  a great  favorite, 
especially  with  inventors  of  semiauroinatic  shoulder  rifles,  as  It  does 
away  with  the  necessity  for  mounting  the  barrel  so  chat  ic  can  slide, 
which  is  a great  complication  in  making  a rifle. 

One  of  the  earliest  successful  machine  guns,  the  Colt,  invented  by 
Mr.  Browning  in  1889,  was  gas-operated.  The  Hotchkiss  gun,  in- 
vented about  the  same  time,  was  also  gasnrtpcratcd,  and  both  of  these 
guns  have  been  used  exteasively  ever  since.  During  World  War  I 
the  Colt  gun  was  modified  somewhat  by  the  Marlin  Arms  Corpora- 
tion, of  fJew  Haven,  though  the  breech  meclunism  retiiained  the  same 
in  principle,  a.s  did  the  const rucriun  of  most  of  the  parts, 

A light  form  of  the  Hotchkiss,  known  as  the  Bencc-Mcrci4,  was 
adopted  as  the  standard  of  the  U.  S.  Army  in  1909  and  remained 
standard  until  1916.  This  also  was  a gas-operated  gun. 

Then  at  the  beginning  of  the  World  War,  Mr.  Browning  submitted 
a model  of  what  he  called  a light  machine  gun  built  on  the  gas- 
operated  principle.  This  gun,  afterward  known  as  the  Browning 
Automatic  Rifle,  was  adopted  and  many  thousands  of  them  were  used 
during  the  World  Wars  I and  II.  While  ic  is  called  an  automatic  rifle, 
the  reader  should  clearly  distinguish  between  this  type  of  automatic 
rifle  which  is  really  a light  mac^ne  gun,  and  the  semiautomatic  rifle 
which  is  a self-loading  shoulder  rifle  to  take  the  place  of  the  Spring- 
field.  Bear  in  mind  that  the  “automatic  rifle*’  and  the  “machine  rifle” 
are  really  light  machine  guns. 

While  the  recoil-operated  principle  as  embodied  in  the  Maxim, 
Vickers  and  Browning  guns  was  more  widely  used  than  any  other, 
the  gas-operated  type  as  exeuipllfied  in  the  Colt,  the  Hotchkiss  and 


^6 


Hatcher’s  Noiewxjk 


tile  Marlin  machine  guns  and  the  Browning,  Bren  and  other  auto- 
matic rifles,  have  been  a close  second  in  popnlaricy* 

As  mentioned  above,  the  gas-operated  system  has  been  the  favorite 
for  semiautomatic  shoulder  rifles,  but  while  a ijreat  many  guns  have 
been  produced  which  operate  on  this  principle,  none  of  them  prior 
to  the  Gar  and  attained  any  lasting  populari^'  or  wide  use.  Among 
the  more  prominent  early  ones  may  be  mentioned  the  Mon  dragon, 
adopted  by  the  Mexican  tiovermnent  in  19U  but  never  very  ex  ten- 
sive] v used;  rhe  “Standard”  automatic  shoulder  rifle  manufactured 
about  1915  as  a sporting  rifle,  and  the  St.  Fticnne  semiautomatic 
shoulder  rifle  used  to  a limited  extent  by  the  French  during  the 
first  World  War. 

In  the  conventional  gas- operated  system  there  is  a hole  drilled  in 
the  barrel,  and  some  of  the  gas  of  the  explosion  passes  through  this 
hole  and  acts  on  a piston  driving  rt  to  the  rear  with  sufficient  force 
to  unlock  and  open  the  breech.  One  of  the  creat  troubles  wkh  rifles 
<jf  this  kind  has  been  the  fact  that  ir  is  difficult  to  control  this  gas 
under  extremely  high  pressure  so  as  to  prevent  it  from  operating 
too  quickly.  In  the  Army  tests  of  the  1930's  an  inventor  named 
White  submitted  n gas-o^rated  shoulder  rifle  in  which  the  front 
end  of  the  gas  piston  is  hollow  and  the  gas  port  is  bored  nor 
only  through  the  barrel  and  through  the  gas  cylinder,  but  through 
the  walls  of  this  hollow  piston  so  that  as  soon  as  the  piston  starts 
to  move  the  gas  port  is  cur  off  after  the  manner  of  the  slide  valve 
in  a srciun  engine.  Thus  gas  can  go  into  the  hollow  piston  only 
before  it  starts  its  motion;  as  soon  as  ic  begins  to  move  the  gas 
supply  is  shut  off  and  the  gas  which  is  already  in  the  piston  is  sup* 
posed  to  act  by  expansion,  therefore  producing  a less  violent  action 
than  would  otherwise  occur.  So  reasons  the  inventor.  However,  other 


designers  state  that  inasmuch  as  the  gas  pressure  in  the  barrel  lasts 
only  about  a thousandth  of  a second,  it  makes  no  difference  whether 
this  cut-off  action  is  ased  or  not. 

Another  inventor  who  attempted  to  gee  away  from  the  brusque 
action  of  die  gas  is  Mr.  Hudson,  who  invented  a machine  gun  in 
which  he  used  the  gas  to  c’Ompress  a spring  which  then  operates 
the  mechanism. 

In  order  to  give  the  reader  an  opportunity  to  study  the  mechanical 
action  of  the  gas-operated  breech  closure  in  detail,  three  diffcrciu 
examples  of  this  type  of  mechanism  will  be  illustrated  with  drawings 
and  descriptions.  The  guns  chosen  for  illustrations  are  the  modified 
Colt,  known  as  the  Marlin,  the  Browning  automatic  rifle  and  the 


Carand  .semiautomatic  rifle. 


Marl  in  Mar  bine  Grtif 

The  mechanism  of  the  .Marlin  machine  gun.  shown  in  Fig  9, 
operates  as  follows:  The  barrel,  yi,  has  a gas  port,  Dy  drilled  in  it 


Figure  9,  Diaeram  of  che  gas-operaied  lype  breech  closure  principle  as  used  in  the  Marlin  niacliine  gun. 


Automatic  Gun  Mechanisms 


Hatcher’s  Notebook 


58 

ac  some  distance  from  the  muzzle.  This  gas  port  communicates  with 
a gas  cylinder  lying  under  the  barrel  containing  a piston  held  in 
its  forward  position  by  a spring.  Jliis  piston  is  arrached  to  the 
bolt,  B,  through  a connecting  rod,  F,  which  is  fastened  to  a pin, 
G,  riding  in  a cam  slot  jn  a wing  on  the  bottom  of  the  bolt.  When 
the  piston  is  forward  the  bolt  is  forward  and  the  rear  end  of  the 
bolt  is  drawn  down  by  the  action  of  the  pin,  G,  in  the  cam  slot, 
until  the  back  surface  of  the  bolt  rests  against  the  locking  shoulder, 
C,  cut  in  the  receiver,  VS'hcn  the  gun  is  fired  the  cartridge  is  held 
firmly  in  place  by  the  bolt,  which  is  locked  in  position  against  the 
shoulder,  C.  After  the  bullet  passes  the  gas  pmr,  D,  near  the  muzzle 
of  the  barrel,  some  of  the  gas  rushes  into  ihc  gas  cylinder  and  im- 
pinges on  the  head  of  the  piston,  D,  driving  it  violently  to  the  rear, 
cogerher  with  its  connecting  rod,  F,  and  the  pin,  Q,  which  is  in  the 
sloe  in  the  bolt.  As  the  pin,  G,  goes  to  the  rear,  the  first  action  is  to 
press  on  the  top  of  the  cam  slot  and  raise  the  bolt  up  out  of  engage- 
ment with  the  shoulder,  C,  after  which  the  bolt  is  carried  to  the 
rear  as  shown  in  the  cm  marked  ''After  Firing.”  This  rearward  mo- 
tion of  the  bolt  ejects  the  empty  cartridge.  The  compressed  return 
spring  immediately  causes  the  piston  to  move  forward,  carrying  the 
bolt  with  it,  until  the  shoulder,  C,  is  reached,  when  the  action  of  the 
pin,  Q,  in  the  cam  slot  again  locks  the  bolt  down  behind  this 
shoulder  and  the  gun  is  ready  for  firing  once  more. 

lirou'wng  A tit  Off /at  ic  Rifle 

The  operation  of  the  Browning  automatic  rifle  is  shown  in  Fig.  10. 
Ill  this  gun  the  barrel.  A,  has  a gas  port,  B.  and  there  is  a piston,  C, 
lying  in  the  gas  cylinder  under  the  barrel.  This  piston  connects  with 
the  bolt,  G,  by  means  of  the  connecting  rod,  I).  However,  instead 
of  being  connected  to  the  bolt  by  means  of  a pin  in  a cam  slot, 
the  connection  in  this  case  is  by  means  of  a linkage  consisting  of 
the  bole  link,  F,  and  the  bolt  lock,  F.  in  the  firing  position  the 
bolt  lock,  F,  presses  against  the  shoulder,  //,  in  the  top  of  the  receiver 
and  this  holds  the  bolt  firmly  in  position  against  the  head  of  the 
cartridge.  When  the  gas  impinges  on  the  cud  of  die  piston,  C,  and 
drives  it  to  the  rear,  the  bole  link,  E,  draws  the  boh  lock  down  out 
of  engagemenc  with  the  shoulder,  f/,  and  then  draws  the  bolt  to 
the  rear,  as  shown  in  the  cur,  “After  Firing.” 

Garcnid  SemmttomaUc  Rifle 

The  principle  of  the  (larand  rifle  is  shown  in  Fig.  11,  which  illus- 
trates the  gas  take-off  used  in  the  first  examples  of  this  gun.  These 
earlv*  Garand.s.  insread  of  having  a conventional  gas  port  drilled  in 
the  barrel,  had  a muzzle  cap,  B,  screwed  on  to  the  end.  After  the 
buliec  had  left  the  rifled  portion  of  the  barrel,  some  gas  went  down 


Figure  10.  Diagram  of  ga^*operaccd  type  br««ch  closure  principle  as  used  in  the  Drowning  auinmatic  rifle. 


AFTER  FIRING 

Figure  II.  Diagram  of  gas*operaicd  lype  brevch  closure  principle  u>eJ  in  the  Garand  semiauiomaitr  rifle. 


Figure  12.  Diagram  of  the  operating  principle  aa  used 


62 


HA'icHiJiR’s  Notebook 


between  this  muzzle  cap  and  the  end  of  the  barrel,  to  strike  on 
Che  piston,  C,  driving  it  ro  the  rear,  together  with  the  operating 
rod,  D,  which  works  the  bole  through  a cam  slot  and  a lug,  £. 

The  bolt  is  of  the  ordinary  rotating  type*  locked  to  the  receiver 
by  locking  lugs  engaging  in  suitable  reces^s.  As  the  piston  goes  back, 
the  earn  sloe,  working  on  the  li^,  £,  first  rotates  the  bolt,  then  car- 
ries it  to  the  rear. 

As  soon  as  the  rearward  motion  is  completed,  the  return  spring 
pushes  the  operating  rod  forward,  closing  the  bolt  and  rotating  it 
into  the  locked  position. 

This  muzzle  cap  arrangemenr  was  soon  abandoned  In  favor  of  a 
convential  gas  port  drilled  near  the  muzzle.  Otherwise  the  principle 
of  the  gun  remains  the  same. 

S^g  PrhtcfpU 

In  [911  Soren  H.  Bang,  of  the  Danish  Recoil  Rifle  Syndicate, 
prcsciKcd  a semiautomatic  shoulder  rifle  to  the  Umced  States  (Jovern- 
inenc  fur  test,  and  this  rifle  functioned  exceptionally  well.  The  prin- 
ciple on  which  it  operated  is  shown  in  Fig.  \ i. 

The  barrel  had  a sliding  cap,  -4,  fitting  over  the  muzzle.  When  the 
bullet  pas.sed  out,  some  of  the  gas  acting  in  the  space  between  this 
cap  and  the  end  of  the  barrel,  pulled  the  cap  forward  as  shown  in 
the  figure  marked  “After  Firing.’*  Ihc  cap,  Ay  was  fastened  to  a 
connecting  rod,  B,  which  operated  a lever,  C This  lever  in  turn  acted 
against  a sliding  breech  cover,  D,  having  in  it  a cam -cut  acting  with 
a lug,  E,  on  the  bolt.  In  the  position  of  rest,  the  bolt  is  locked 
to  the  barrel  by  the  locking  Jugs,  F,  in  the  locking  recess,  G. 
When  the  gun  is  fired,  the  gas  escaping  from  the  muzzle  pulls  the 
muzzle  piece,  A.  forward,  thus  causing  the  lever,  C,  to  throw  the 
sliding  brccch  cover,  D,  quickly  to  the  rear.  As  this  cover  goes  to 
the  rear,  the  cam  slot  acting  on  the  lug,  turas  the  bolt  so  as  to 
unlock  it  and  then  carries  the  bolt  to  the  rear  along  with  the  breech 
cover.  There  is  a return  spring  under  the  barrel  which  is  connected 
to  the  breech  cover  through  a rod,  H.  As  soon  as  the  rearward  morion 
I is  arrested,  the  spring  pulls  the  breech  cover  forward  again  and  when 
the  forward  tnorion  of  the  bolt  is  completed  the  cam  slot  in  the 
cover  acting  on  the  lug,  £,  again  locks  the  bolt  to  the  rear  end  of  the 
barrel. 

Frhner  Actuated  Type 

Among  the  many  novel  ideas  for  operating  a semiautomatic  rifle, 

I is  the  scheme  for  allowing  the  primer  to  move  enough  in  the  cart- 
ridge case  ro  unlock  the  breech  mechanism.  If  the  head  of  the 
cartridge  were  supported  around  rhe  edge  only,  leaving  the  primer 
free,  the  primer  would  move  back  under  the  pressure  of  the  gas 
1 when  the  gun  is  fired,  and  if  it  were  allowed  enough  freedom  it 


Automatic  Gun  Mrchakcsms 


^3 

would  be  blown  entirely  out  of  the  cartridge  csi^e.  However,  it  is 
possible  to  control  this  morion  and  allow  the  primer  to  move  back 
just  a few  hundredths  of  an  inch,  utilizing  this  short  but  powerful 
morion  ro  impart  energy  enough  to  the  moving  actuator  to  cause 
it  to  unlock  the  brccch. 

Gar/md's  hivcntion 

In  the  first  World  VV'ar,  John  C.  Garand,  a iiiachine  designer  living 
in  New  York,  began  working  on  the  design  of  a light  machine  gun 
to  be  operated  by  the  set-back  of  the  primer  in  its  pocket.  The  primer 
was  to  be  allowed  to  move  back  slightly,  and  in  so  doing,  it  was  to 
transmit  this  motion  through  the  firing  pin  to  an  actuator  which 
would  open  rhe  brccch  and  extract  the  empty  cartridge,  after  which 
the  gun  would  be  reloaded  by  the  action  of  a spring  which  had  been 
compressed  during  the  first  motion.  The  United  Stares  Rurcau  of 
Standards  at  Washington  being  anxious  to  aid  the  war  ell or t,  em- 
ployed Mr.  Garand  and  provided  him  with  facilities  to  work  on  the 
itivention. 

When  the  gun  was  examined  by  the  Ordnance  Department  in 
u;i9,  ic  was  seen  to  be  exceptionally  well  designed,  and  was  con- 
sidered to  have  such  promise  that  Mr.  Garand  was  hired  and  sent  to 
Springfield  Armory,  where  he  has  remained  as  an  Ordnance  Kngitieer 
ever  since. 

Early  models  of  Mr,  Garand's  gun  worked  well  in  tests,  but  just 
about  the  lime  he  had  his  second  and  much  improved  model  nearly 
perfected  and  ready  for  adoption,  chc  type  of  powder  was  changed 
from  the  old  fast  burning  pyro  to  the  progressive  burning  Improved 
Milirarv  Rifle  power,  in  which  the  first  rise  in  pressure  was  not 
nearly  so  rapid. 

Mr.  Garand  was  much  disappointed  when  his  mechanism,  which  up 
CO  now  had  done  so  well,  failed  to  function  reliably  with  the  new 
type  of  powder.  He  thereupon  dropped  the  primer  actuated  system 
and  switched  over  to  the  gas  operated  type  of  gun  for  his  future 
work  along  this  line  which  eventually  resulted  in  the  production 
of  the  present  U.  S.  Rifle  Cal.  .50  .M  1. 

In  spite  of  the  fact  that  this  rifle  is  not  now  being  used,  a description 
of  the  mechanism  is  included  here  because  the  novelty  of  this  principle 
makes  it  interesting  ro  any  student  of  fircarnis. 

Referring  to  Fig.  i},  A is  the  barrel  screuxd  onto  the  receiver,  B. 
C is  the  breech  block  containing  inside  of  it  a moving  actuator,  G, 
arranged  to  have  motion  imparted  to  it  by  a slight  motion  of  the  firing 
pin,  F.  When  the  gun  is  fired  the  firing  pin  moves  back  about  three- 
hundredths  of  an  inch.  This  modem  is  very  quick  and  imparts  a 
considerable  blow  to  the  actuator,  G,  which  travels  rapidly  to  the  rear. 

The  bole  up  to  this  time  has  been  locked  to  the  receiver,  by  the 
locking  block,  D,  bearing  on  the  shoulder,  E.  As  the  actuator  goes 


Garancl’s  fine  ^crabuiotiiaik  rifle,  a primer  jctuaied  model  buili  at  Sprinj^Jield  in  1920.  It  u>ed  die  service  .k)  caliber  canridcc. 


Gacand’s  )c^uad  primer  aauac^d  .30  ca liber  model,  produced  ai  Springfield  Armor>'  in  1921.  Ic  did  nm  ii«e  a laming  bole,  as 
did  the  first  model.  The  bolt,  which  moves  back  and  forth  in  a Mraighi  line,  was  locked  by  a piece  of  steel  hinged  at  its  rear  end, 
and  fitted  to  be  lifted  or  depressed  by  the  motion  of  an  actuator  inside  the  breech  block.  When  the  gun  was  fired,  ibe  primer  was  allowed 
to  move  hack  .U55  inch,  and  this  motion,  transmitted  ihrniigh  ihe  firing  pin  to  the  actuator,  operated  the  gun. 


. A 

Hatch  fiiR’s  Nuiicbook 


Figure  13.  Oi&gram  of  |>Hiner*accMfl(^  rype  hrcecli  closure  principle 
used  in  an  early  experimental  Garand  remiauiomafic  rifle. 

to  chc  rear  chc  cam  surface  lifts  this  locking  block  nut  of  engagement 
with  chc  receiver  and  the  bolt  then  moves  to  chc  rear  wicfi  the  ac- 
Tnator  against  chc  action  of  the  return  spring,  which  causes  ihc  parts 
to  move  forward  again  as  soon  as  the  rearward  motion  is  completed. 

CMer  .22  Mdch'mc  Gun 

While  most  of  the  principal  methods  of  operating  machine  guns 
and  semiau  coma  tic  rifles  have  been  described  above,  one  can  never 
he  sure  when  an  inventor  will  come  in  with  something  entirely 
new  and  different.  For  example  some  time  ago  a desire  was  ex- 
pressed bv  the  Army  for  sonic  means  of  shooting  caliber  .22  cart- 
ridges in  a machine  gun.  It  was  desired  tu  do  this  for  two  reasons; 
first,  because  it  was  thought  that  by  u?nng  the  verv  cheap  and  in- 
expensive caliber  .22  cartridges  for  machine  gun  practice  in  time 
of  peace,  a great  deal  of  training  could  be  obtained  without  expend- 
ing the  expensive  full  powered  cartridges  and,  consequently,  much 
money  would  be  saved;  and  in  addition,  it  was  desired  to  find  some 
safe  method  of  allowing  troops  to  obtain  antiaircraft  practice  with 
machine  guns,  which  in  most  military  posts  cannot  be  accomplished 
with  full  powered  cartridges  because  the  great  power  and  range  of  the 
Army  cartridge  makes  it  dangerous  to  fire  at  high  elevation. 

At  first  glance  it  seemed  very  difficult  to  construct  a machine  gun 
chat  would  work  with  the  low  powered  caliber  .22  cartridge,  but  a 
voung  mechanic,  David  M.  Williams,  of  Godwin,  North  Carolina, 
appeared  in  the  Ordnance  Office  and  offered,  not  to  make  a special 


Automatic  Gun  Mechanisms 


67 

machine  gun  for  .32's,  but  to  take  a heavy  Bro%vning  gun  and  operate 
its  massive  mechanism  with  the  .22  cartridge.  This  feat  appeared  so 
absolutely  impossible  rhac  the  arms  experts  had  not  even  given  it  any 
consideration,  but  when  this  young  inventor  outlined  his  proposed 
method  of  doing  the  job  he  was  given  the  order  to  proceed.  In  six 
weeks  he  modified  a Browning  machine  gun  so  that  it  operated  in  a 
normal  manner  with  the  caliber  .22  cartridges  with  never  a malfunc- 
tion. The  Browning  gun  is  a rccoil-opcrated  gun  and  the  caliber  .22 
cartridge  does  not  have  a fraction  of  riie  recoil  pow'er  to  operate  this 
gun,  but  Mr.  Williams  accomplished  his  job  by  making  the  chamber 
of  the  gun  in  a separate  piece  from  the  barrel,  somewhat  in  the 
same  way  as  the  cylinder  or  the  revolver  is  separate  from  the  barrel. 
The  separate  chamber,  however,  instead  of  being  outside  the  barrel 
is  in  the  form  of  a hollow  piston  fitting  into  the  rear  end  of  the 
barrel.  When  the  gun  is  fired  the  gas  of  the  explosion  gets  into  the 
space  between  the  face  of  the  chamber  and  the  rear  end  of  the  barrel, 
and  olie  pressure  of  the  gas  is  sufficient  co  force  the  separate  chamber 
backward  with  more  chan  enough  recoil  to  operate  almost  any 
mechanism. 

The  Colt  Service  Model  Ace  ^22  Caliher  Pistol 

Tills  is  another  well  known  adaptation  of  the  Williams  Floating 
Chamber.  I:  is  a replica  of  the  Army  45  Biscol,  M.  1911  Ai,  only 
it  is  made  to  shoot  the  ordinary  .22  long  rifie  cartridge.  I'hrough 
the  action  of  the  floating  chamber,  the  .22  caliber  caitndge  is  given 
enough  power  to  function  the  slide  with  enough  energy  co  give  a 
very  good  imitation  of  the  recoil  experienced  w'ith  actual  .45  caliber 
cartridges. 

The  utility  of  this  gun  is  to  give  practice  in  handling  the  service 
sideann,  includiug  rapid  fire  practice,  without  the  expense  of  using 
the  full  powered  loads.  Tiie  aciiori  of  this  gun  will  be  readily  under- 
stood from  the  accompanying  jllustratinns. 

The  Short  Stroke  Piston  Vrlticiple 

In  1940  the  Winchester  Repeating  Arms  Co.  submitted  for  test 
a 9/^)  pound  Cal.  30  semiautomatic  rifle  operating  on  the  short  stroke 
piston  principle,  patented  by  Mr.  David  M.  Williams. 

The  gas  is  taken  off  near  die  breech,  where  the  pressure  is  very 
high.  Tne  piston  is  completely  housed  in  the  cylinder,  and  is  per- 
mitted to  move  through  a stroke  of  only  about  a tenth  of  an  inch. 
Ac  the  rear  of  its  stroke,  it  acts  as  a valve,  and  prevents  the  gas  from 
escaping  from  the  gas  cylinder  except  by  going  back  into  the  barrel 
through  the  port  by  w'liich  it  entered  the  gas  cylinder. 

The  operating  slide  rests  against  the  projecting  end  of  the  piston, 
which,  under  me  impact  of  the  gas,  strikes  the  operating  slide  a 
sharp  blow.  Even  the  short  piston  .<:troke  imparts  co  the  operating 


Diagram  showing  ihe  action  oi  the  floating  chamber  in  the 
Colt  Service  Model  Ace.  The  barrel  is  pifinH  lo  ihc  receiver 
by  the  slide  stop,  and  amaut  move.  Upon  flring,  the  pressure  of 
(he  gas  on  the  front  end  of  the  movable  chamber  drivtss  it  to 
ihc  rear  until  the  lug  on  the  bottom  strikes  a corresponding 
lug  on  the  barrel,  and  stops  the  motion.  As  the  floating 
chamber  rests  against  the  breech  block,  w'hicfa  is  part  of  the 
slide,  this  motion  is  transtnicted  to  the  slide,  which  is  thus 
thrown  to  the  rear  against  die  action  of  the  rectMl  spring,  at 
the  same  time  cockfng  the  hammer  and  compressing  the  main- 
spring. 


w 


. •A 


Hatcher’s  Xoteb<X)K 


Auit)MATiC  Guw  iMechanisms  69 

slide  sufficient  energy  to  cause  it  ro  carry  through  and  cjpenUe  the 
mechanism. 

It  is  something  like  the  actiun  of  a croquet  Ua\]  held  under  the 


AcHon  oi  (h«  du»iuia  diauiber  lu  die  CoU  SeevUe  ModeJ  Ace. 

Upper;  Posidon  of  (he  pans  it  the  loscaoc  of  The  floadag  diiituber 

with  the  carer  id  is  held  forward  by  (he  slide  under  pressure  of  the  recoil  spring. 
The  barrel  is  lield  fast  to  the  receiver  aod  cauaoi  move. 

Lower:  The  gua  has  jnsc  been  hred»  and  gas  pressure  (iudicaied  by  arrows) 
acts  on  the  inside  surface  of  (he  cartridge  head  and  on  the  front  face  of  the 
chamber  to  drive  (he  chamber,  cartridge  case  and  slide  to  the  rear.  When  the 
Boating  rhamher  has  moved  a short  dilsiance  to  ihe  position  shown,  its  motion 
is  arrested  by  a Up  on  the  botlom,  which  strikes  a corresponding  Itp  nn  the  barrel. 
Tl)c  momentum  which  the  slide  has  acquired  a tries  it  on  to  the  rear. 

foot  and  struck  a sliarp  blow  with  a mallet  while  another  hall  rests 
freely  against  the  far  side.  The  second  ball  will  be  driven  swiftly  away 
by  che  elastic  impact. 

This  same  principle  was  used  in  the  Winchester  Carbine  which  was 
adopted  by  the  Army  in  1941  as  the  U.  S.  Carbine  Caliber  .30,  M i. 

This  s>'stem  has  the  great  adv^tage  of  doing  away  with  the  long 
operating  rod;  moreover,  the  power  of  the  gas  impact  on  the  piston 
is  so  great  that  there  is  little  or  no  danger  of  having  the  piston  stick 
from  fouling  or  other  cause.  The  ga.s  impact  slaps  the  piston  to  the 
rear  i/io  of  an  inch;  then  the  operating  slide,  driven  forward  by  the 
return  spring,  slaps  it  back  again. 


V 


Notes  on  Machine  Guns  and 
Their  Development 

Guns  which  arc  capable  of  delivering  cominuous  fire  as  long  as 
the  trigger  is  helct  and  while  die  ammunition  supply  holds  our 
are  in  the  main  called  madiine  guns,  though  there  is  ano^er  nomen- 
clacure  used  in  our  army  for  the  very  Tight  fully  automatic  guns 
capable  of  being  fired  from  the  shoulder,  which  are  called  “automatic 
pines,”  as  distinguished  from  the  semi-automatics  which  require  a 
separate  pull  of  the  trigger  for  each  shot. 

The  mechanical  principles  used  to  operate  these  automatic  weapons 
will  be  described  in  the  following  chapter.  Here  we  propose  to 
set  down  1 very  brief  history  of  the  development  of  the  machine  gun, 
together  with  some  information  on  the  various  types  which  have  been 
or  still  are  standard  weapons  of  our  army,  as  well  as  some  informa- 
tion on  the  principal  foreign  types. 

Machine  guns  as  a class  are  not  a very  new  invention,  for  some 
type  of  gun  capable  of  firing  more  than  one  shot  at  a time  has 
been  the  goal  of  inventors  ever  since  the  beginning  of  firearms  history, 
and  many  inventions  of  this  class  were  triec  out  in  the  days  of  muzde 
loaders,  and  perhaps  even  before  chat,  for  it  is  said  chat  there  was  a 
cross-bow  used  at  rhe  Battle  of  Hastings  in  1066  A.  D.  which  was 
capable  of  firing  ten  arrows  at  one  time. 

From  the  earliest  days  of  firearms  until  the  present  time,  the 
e/Torr  to  increase  the  volume  of  fire  obtainable  from  a single  weapon 
has  been  continuous,  and  this  has  resulted  in  the  production  of  an 
innumerable  host  of  contrivances,  most  of  which  were  merely  curios 
hut  a few  of  which  were  useful. 

In  the  era  of  the  muzzJe  loader,  the  machine  guns  of  that  time 
usually  took  the  form  of  a row  of  musket  barrels  mounted  side 
by  side  in  a frame  like  the  pipes  of  an  organ,  and  arranged  so  that 
they  could  be  fired  one  at  a time  or  all  together.  'ITicse  contrivances 
were  called  “organ  guas.”  In  general  they  were  nor  much  of  a suc- 
cess. In  the  first  place  they  were  heavy  and  clumsy  to  handle,  but  this 
was  not  their  greatest  disadvantage.  That  was  the  fact  that  after  all 
the  barrels  had  been  fired  in  rapid  succession,  thus  gaining  quite  a 
volume  of  fire  for  a short  time,  this  period  of  useralness  was  im- 
mediately follow'ed  by  the  long  interval  of  inaction  necessary  to  re- 
load separately  each  of  the  muzzle-loading  barrels. 

A much  improved  gun  of  this  gwicral  type,  called  the  “Requa 
batterj’,”  w'as  used  in  the  late  stages  of  the  American  Civil  War. 

70 


Machinf  Guns  akd  Their  Develoi^men  r 


7* 


Hie  gan  had  a sliding  breechblock  which  could  be  operated  bv  a 
lever,  and  when  rhe  breechblock  was  opened  the  gun  could  be 
charged  with  special  cartridges  which  were  held  in  a Tong  strip,  be- 
hind whicli  the  breechblock  was  closed  by  the  lever  handle.  Each 
cartridge  had  in  the  back  end  a hole  w^lich  communicated  with  a vent 
in  the  breechblock.  The  vents  were  all  connected  together  hy  a hole 
extending  through  the  entire  length  of  the  breechblock  and  arranged 
CO  be  filled  with  fine  powder.  In  the  middle  of  ri^c  breechblock  was 
a regular  percussion  lock  with  a hammer,  and  a nipple  for  a cap. 
When  this  cap  was  fired  the  fiame  spread  from  the  center  toward 
each  end  of  the  breechblock,  and  chc  cartridges  were  ignited  succes- 
sively. The  reloading  could  be  done  with  reasonable  rapidity  as  all 
that  was  necessary  was  to  replace  the  strip  of  cartridges,  place  some 
powder  in  chc  comiTiiinicating  channels,  cock  chc  hammer,  and  place 
a new  cap  on  the  nipple. 

Another  old  Civil  War  machine  gun  embodied  chc  principle  of 
the  revolver.  This  gun  used  cap  a«d  ball  ammunition  which  was 
loaded  in  steel  containers,  whiol)  served  the  double  purpose  of  car- 
tridges and  explosion  chambers,  as  the  containers  did  noi  enter  the 
barrel  of  rhe  gun  at  all  but  during  the  explosion  were  held  dose 
behind  the  barrel  but  in  line  with  it,  like  the  chambers  of  a revolver. 

To  prepare  the  gun  for  action,  a number  of  the  containers  were 
loaded  with  powder  and  ball  and  each  was  primed  by  placing  a per- 
cussion cap  on  the  nipple.  The  loaded  containers  were  then  placed  in 
a hopper  on  top  of  tne  gun,  and  upon  turning  the  crank  chc  charges 
were  fed  down  into  gro<ivc>  on  the  edge  of  a revolving  cylinder 
whicli  carried  them  past  the  breech  end  of  the  barrel,  where  they 
were  success! vdy  fired,  each  empty  container  being  rolled  out  on 
the  far  side  of  the  breech  as  a fresh  one  was  being  fed  up,  This  gun 
had  only  one  bar  ref,  which  was  consequently  subject  to  overheating 
and  excessive  fouling  from  the  residue  of  the  black  ptiwder  which 
was  used  in  those  days. 

9 


The  Gatlhi^  Gun 

The  first  really  practical  and  successful  machine  gun  was  invented 
on  November  4,  1862,  by  Dr.  Richard  J.  Gatling.  The  Gatling  gun 
was  somewhat  similar  to  the  revolver  gun  described  above,  in  that 


ifr^lyfr^rnsfct 


MachiiNe  Guns  and  Their  Devei^pmf.nt  73 

in  line  wirh  its  respective  barrel  until  it  was  fired  and  finally  ejected 
from  the  gun.  In  this  way  each  barrel  was  fired  only  once  for  each 
revolution,  and  the  heating  and  fouling  effects  were  greatly  reduced. 
An  additional  advantage  was  the  fact  that  hang  fires  were  rendered 
cmnpararivciy  harmless,  as  die  cartridge  was  always  in  line  with  the 
barrel. 

As  tins  invention  occurred  during  a war,  the  promoters  ft>und  an 
ea^y  way  to  demonstrate  it  hy  bringing  the  gun  out  on  a battlefield, 
and  firing  at  an  actual  enemy. 

As  soon  as  the  self-contained  metallic  cartridges  were  invented, 
great  improvements  in  the  Gatling  mechanism  were  made  and  the 
number  of  barrels  was  increased,  usually  to  ten. 

The  Gatling  gun  was  adopted  bv  many  nations  and  enjoyed  a 
h>ng  period  of  popularity.  It  w»as  really  a most  effective  weapon  and 
had  some  very  good  feaiiu'cs.  In  our  own  service  it  was  the  standard 
machine  gun  as  lately  as  during  the  Spanish- American  War.  In  the 
Santiago  campaign  both  automatic  machine  guns  and  the  Gatlings 
were  used  side  by  side,  and  the  Gatlings  seemed  to  be  the  more 
effective  at  chat  time. 

The  Mitrailleuse 

During  the  Civil  War  many  experimental  guns  w'crc  tried,  but  as 
this  was  before  the  days  of  metallic  cartridges,  none  were  very 
successful  and  all  were  considered  freaks  or  experiments,  as  indeed 
they  were.  As  the  Gatling  came  out  near  the  end  of  the  war,  it 
passed  practically  unnoticed.  After  the  war  it  gradually  became 
popular,  but  before  it  reached  this  popubrity  the  Franco-Pnissian 
War  occurred,  and  the  French  invented  a machine  gun  called  the 
‘‘mitrailleuse,'*  whic-h  created  a great  sensation  at  that  time. 

The  w'ord  “mitrailleuse”  conies  from  the  French  word  ?/titraiIle, 
meaning  small  cannon  balls  or  grape  shoe.  The  French  now'  call  all 
machine  guns  by  this  name,  and  they  also  call  a machine  gunner  a 
mhrailkur  (or  grape  shooter).  The  name  originated,  however,  with 
the  weapon  which  Napoleon  III  used  against  the  Prussians  in  1870, 
This  consisted  cf  25  rifle  barrels  fastened  together  into  a parallel 
bundle  and  encased  so  as  to  resemble  a field  gun.  The  breech  of 
the  gnn  could  be  opened  to  allow  a block  coiiraiiiing  23  cartridges  to 
be  inserted.  Each  of  the  holes  in  the  block  registered  with  one  of  the 
barrels.  After  the  breech  was  ck»sed,  a turn  of  the  handle  released 
the  25  firing  pins,  one  after  the  other,  thus  firing  a volley  of  25  shots, 
which  could  be  made  slow  or  fast  according  to  the  speed  of  the 
firing  handle.  The  gun  was  capable  of  firing  about  125  shots  a minute. 

The  advent  of  brass  cartridge  ca.scs  had  removed  Jiianv  difficulties 
attending  the  invention  of  machine  guns,  and  the  mitrailleuse  was 
really  a formidable  weapon.  This  gun  was  adopted  a year  or  two 
before  the  Franco-Prussian  War,  and  its  construction  and  operation 


Hatcher’s  Notebook 


74 

were  kept  a deep  secret.  Though  efforts  were  made  to  keep  the 
actual  details  of  the  guns  secret,  their  existence  was  widely  heralded, 
and  the  French  were  told  that  they  had  a weapon  which  would  make 
them  invincible,  and  would  render  victorj'-  easy  and  sure, 

The  fame  of  this  invention  and  the  secrecy  surrounding  its  actual 
use  proved  its  undoing.  The  Prussians  heard  of  the  wonderful  new 
gun,  and  from  what  the)*  knew  of  the  Gatling  and  other  machine 
guns  they  were  sure  that  they  had  a formidable  antagonist.  TTterefore 
chev  set  about  wicli  characteristic  enei^y  and  strategy  to  compass 
its  downfall,  in  which  they  Averc  most  successful.  They  realized  that 
the  French  were  well  supplied  with  these  weapons,  and  that  what 
few  machine  guns  they  themselves  could  obtain  would  not  be 
sufficient  to  counteract  it.  Accordingly,  for  the  purpose  of  producing 
a moral  effect,  they  scorned  the  Gatling  and  such  other  machine 
guns  as  they  could  have  obtained,  and  rostered  a contempt  for  all 
weapons  of  this  class.  At  the  same  time,  they  carefully  mstnicred 
the  artillery  to  concentrate  on  the  mitrailleuses  whenever  they  ap- 
peared, and  to  insure  their  destruction  at  all  costs. 

In  addition  to  this  handicap,  the  iiiitrailleuscs  went  into  the  war 
practically  unknown  to  the  army  chat  was  to  use  them.  They  were 
kept  about  as  much  a secret  from  the  army  as  from  ihe  pubfic,  and 
the  result  w'as  that  the  personnel  was  unfamiliar  with  the  mechanism, 
and  chat  no  proper  tactics  had  been  worked  out.  When  the  guns 
were  finally  brouglit  into  action  they  were  used  as  artillery,  and  not 
as  infantry  weapons,  and  the  usual  result  was  that  they  were  quickly 
destroyed  by  rhe  German  artillery.  In  one  or  two  instances  they 
were  used  with  effect,  but  in  general  they  were  a failiuc.  The 
German  strategic  fiction  that  machine  guns  were  useless  soon  came 
to  be  believed  mn  only  bv  the  Germans  themselves  but  by  everyone 
else,  and  the  adoption  o(  machine  guns  by  all  nations  was  delayed 
for  years  by  the  fiasco  of  the  mitrailleuse,  the  machine  gnn  field  for 
some  years  following  being  largely  filled  by  the  Gatling  gun. 

It  will  be  observed  by  the  reader  that  up  to  this  time  all  the  guns 
described  were  hand-operated  guns,  or  guns  in  which  the  muscular 
power  of  the  operator  was  used  by  means  of  a crank  or  lever  to  do 
the  loading  or  unloading.  For  example,  in  the  Gatling,  one  man  put 
the  cartridges  into  the  gnn  while  another  man  turned  the  crank 
conrinuously  as  long  as  he  wanted  the  g\m  ro  shoot. 

'Hje  Maxim  Guft 

It  was  inevitable  that  sooner  or  later  some  inventor  would  discover 
a way  to  make  the  gun  fully  automatic,  diat  is,  to  utilize  part  of 
the  force  of  the  explosion  for  throwing  out  the  empty  shell,  operating 
the  mechanism  of  rhe  gun,  and  putting  in  a new  shell.  This  was 
accomplished  in  1884  by  Sir  Hiram  Stevens  Maxim,  who  produced 
the  first  successful  automatic  gun;  and  today  in  nearly  its  original 


jion  of  50  year$  A >ery  «arly  of  the  Mavim  ai  ihc  end  of  a 20.000  round  endurance  itH  a(  Sprini;tic!<J 

was  imo  a sand  pile  in  (he  mom  in  from  of  ihe  £un.  The  ca^rld^es  are  the  rimmed  type  of  .50  caliber  used  in 
ra>:  Model  of  1S92.  It  is  imerescing  to  note  that  there  i<  vert  licilr  dilTcrcmc  between  this  early  machine  cun  and  some 


Maxim  machine  ^un  model  of  1904.  Thii  hca\*>  i>pe  machine  gun  yi-A>  in  u^e 
by  nur  Army  from  chc  cime  of  i(5  adopciort  up  until  the  beginning  of  VX'or'd  VC'ar  I 


•hJ 


.MaCIIINI*.  itlSh  AM>  Thur  DiAKI.OI'.MKNT 


Hatch F.K*5  Notebook 


78 

form  it  remains  one  of  the  leading  machine  guns  of  the  world, 
though  it  is  now  kno\vTi  principally  by  the  name  of  V'^ickers,  from 
the  firm  which  made  it  for  so  many  years.  This  firm  was  first  known 
as  Vickers  Sons  Sf  Maxim,  but  is  now  Vickers,  Llniiccd. 

Alaxim  was  an  ^\merican,  traveling  in  Europe  at  the  time  of  this 
invention.  In  a letter  to  the  editor  of  the  London  Star,  in  1915,  he 
gives  the  following  account  of  how  it  happened  that  his  inventive 
efforts  were  turned  to  the  field  of  nrcaruis: 

“In  188 1 I visited  the  Electrical  Exhibition  in  Paris,  and  was  made 
a Chevalier  of  the  Legion  of  Honor  on  account  of  some  electrical 
and  chemical  work  I had  done;  and  about  a year  later  I was  in  Vienna 
where  I met  an  American  w'honi  I had  known  in  the  States.  He  said; 
‘Hang  your  chemistry  and  electricity!  If  you  wish  to  make  a pile  of 
money,  invent  something  that  will  enable  these  Europeans  to  cut  each 
other’s  rluoats  with  greater  facility.’ 

‘‘This  made  me  chink  of  the  time  when  I was  about  14  vears  of 
age  and  was  making  drawings  for  my  father  of  a ban  cl  worked 
machine  gun.  I also  thought  of  the  powerful  kick  1 got  the  first  time 
I fired  a United  Scares  military  rifle.  On  my  return  to  Paris  I nude 
a very  highly  finished  drawing  of  an  automatic  rifle.  Happening  to 
meet  a Scotchman  in  Paris  whom  I had  known  in  the  States,  I showed 
him  my  drawings.  He  invited  me  to  come  to  London.  I did  so;  and 
shortly  after  I started  an  experimental  shop  at  5yd,  Hatton  Garden,” 

Tlie  Maxim  gun,  de«»cribed  on  page  247,  has  a very  simple  and 
reliable  action,  and  for  many,  many  years  has  given  extremely  satis- 
factory functioning  wherever  it  wa.s  properly  used. 

As  long  as  the  firing  mechanism  is  held  down  this  gun  will  con- 
tinue to  reload  and  fire  amonidtically  at  a race  of  about  450  rounds 
per  minute  until  the  belt  of  250  cartridges  is  exhausted,  when  a new 
belt  must  be  fed  in  and  the  gun  loaded  with  the  motion  of  the  crank 
on  the  side,  after  which  it  is  ready  to  fire  again. 

The  gun  is  ordinarily  fired  from  a tripod  which  enables  it  to  be 
controlled  for  both  elevation  and  direction.  Owing  to  the  intense 
heat  of  firing  so  many  cartridges  in  rapid  succession,  the  gun  would 
become  red  hot  in  a very  short  time  unless  some  special  means  of 
cooling  were  adopted.  For  this  reason  there  is  a water  jacket  sur- 
rounding the  barrel,  which  holds  7 14  pints  of  water.  The  water 
in  the  jacket  begins  to  boil  after  600  rounds,  and  then  evaporates 
at  the  rate  of  i !4  pints  for  each  thousand  rounds. 

The  Vickers  gun  wciglis  38  pounds,  including  the  water  in  the 
jacket,  and  the  tripod  weighs  35  pounds. 

In  1904  the  heavy  Maxkn  gun  was  adopted  as  standard  for  the 
United  States  Army,  to  be  superseded  in  1909  bv  the  Benet-Mcrcic, 
which  will  be  described  later.  In  1916  the  Vickers  gun,  which  was 
a lighter  edition  of  the  same  type  of  mechanism  as  the  Maxim,  was 


Machine  Guns  and  Their  Development 


79 

adopted  as  the  Army  standard,  and  many  Vickers  guns  were  used 
during  World  War  I. 

The  Colt  Machine  Qun 

The  invention  of  the  jVlaxim  machine  gun  was  followed  by  the 
design  of  a gun  by  John  Browing,  of  Ogden,  Utah,  which  after- 
ward became  known  as  the  Colt.  Mr.  Brovming  produced  the  first 
model  of  this  gun  in  1889. 

In  this  connection,  the  following  letter  will  be  of  interest  as 
establishing  the  date  when  Mr.  Browning  made  this  invention. 

Hartford,  Conn., 

Dec.  20,  1917. 

Capt.  J.  S.  Hatcher, 

Springfield  Armory, 

Springfield,  Mass. 

Sir: 

In  regard  to  uur  recent  convervaaon,  would  say  that  ciic  application 
for  the  first  machine  gun  patent  granted  to  niy  father  was  filed  Jan. 
d,  1 890. 

This  arm  was,  more  properly  speaking,  of  the  machine  rifle  class, 
willing  less  than  12  pounds,  and  meant  to  be  fired  from  the  shoulder. 

ihe  mechanism  was  operated  by  means  of  a lever,  or  “flapper,'* 
which  was  pivuced  near  the  forward  end  of  the  barrel;  this  lever 
being  actuated  by  the  gases  at  die  muzzle.  The  g\in  rook  the  .44 
Winchester  black  powder  cartridge,  and  fired  at  the  rare  of  about 
16  shots  per  second.  A model  of  this  gun  was  made  early  in  the 
year  1889. 

As  far  as  I can  learn,  this  was  the  first  effort  of  my  father's  in 
the  machine  gun  line,  his  time  previous  to  this  being  taken  up  in 
designing  the  Winchester  repeating  and  single  shot  firearms  which 
are  still  on  rhe  market. 

Thanking  you  for  your  courtesy  extended  to  me  at  Springfield 
Armory,  I am, 

Respectfully, 

V.  A.  Browning 

About  1892,  Mr.  Browning  brought  an  improved  version  of  this 
invention  to  the  Colt  factor)'  at  fwrtford,  where  it  was  perfected 
and  put  into  production  as  the  Colt  Machine  Gun.  Model  of  1895. 
This  gun  was  adopted  by  the  Nav>%  and  then  by  the  Army,  and 
was  used  in  the  Spanish  American  w'ar  of  1898,  along  with  a number 
of  the  old  hand  operated  Gatlings. 

This  gun  did  not  have  a water  jacket  for  cooling,  as  did  the  Maxim. 
Instead,  it  had  the  barrel  made  as  heavy  as  practical,  to  enable  a 
number  of  shots  to  be  fired  before  the  barrel  would  become  too  hot 


8o 


HAiaTFR’s  NarEBOOK 


for  opefiuioii.  One  disiui vantage  of  Hiis  gun  was  that  when  the  finger 
\va?  removed  frt>tn  the  IriL^ger,  the  breech  remained  closed  on  a li\  c 
cartridge.  If  a long  burst  of  sfiots  had  l»ccn  fimi,  the  barrel  v tmld  l>e 
so  hot  that  the  round  thus  left  in  the  hot  chamber  would  go  off 
from  the  heat  in  a short  time.  'I'he  renicdy  was  for  the  gnnncr  to 
unload  the  gun  at  each  intermptioit  of  fire. 


One  of  (he  original  Browning  designed  Model  189$  Coh  n^achlne  guns  in  ii^e 
during  die  Spanish  Ameciidii  War  of  IH98  un  board  die  U.S.S,  Ailecn. 


The  weight  of  the  Colt  gun  was  about  3^  pounds,  and  it  used 
ii  tripod  weighing  .some  56  pounds.  IJkc  the  .Maxim  and  the  Vickers, 
it  was  fed  from  belts  holding  250  rounds.  However,  these  belts 
were  much  simpler  and  cheaper  to  make  than  the  ones  used  by 
Maxim  type  guns. 

When  World  War  I brolcc  out  in  1914,  the  Russians  placed  a 
large  order  for  Colt  guas  with  the  Marlin-Rock  well  Co.,  of  New 
Haven,  and  when  we  entered  that  war  in  1917.  we  purchased  some 
:50c  of  these  Colt  guns  from  Marlin.  These  were  used  during  the 
early  part  of  that  war  for  training,  then  became  obsolete  as  far  as 
our  army  was  concerned.  No  Colt  guas  of  that  type  have  been  made 
since  1917.  However,  this  gun,  in  a modified  form  known  as  the 
Marlin,  saw  very  extensive  service  in  b<Kh  aircraft  and  cank.s  in  zgi8. 


'-•V 

Colt  machine  gun,  invented  by  Bowniny  in  188).  The  gas  passing  through  a port  alvmt  six  inches  behind  the  muzzle  Impinged  on 
a lever  pivoted  under  the  gun,  swing  it  downward  and  backward  to  actuate  the  mechanism.  The  present  author  is  sbowd  liriiig  une 
of  these  guns  in  19 P.  when  the\  were  being  made  for  the  Russians  hy  Marlin -Rockwell. 


82 


lfATaiLK*s  Notebook 


The  Marlin  Macbina  Gun 


When  we  entered  the  first  world  war  we  were  desperately  in  need 
Ilf  machine  giin>  of  any  kind,  but  cspcciallv  of  a type  that  could  be 
mounted  on  the  aircraft  of  that  day  and  synchronized  so  as  to  fire 
through  the  propellers  without  hitting  them.  The  engineers  of  the 
Marlin  Rockwell  Co.  therefore  decided  to  attempt  a conversion  of 
the  Colt  gun  to  one  that  would  be  suitable  for  this  purpcfsc.  I’hc  action 
is  described  on  page  56. 

1‘hc  swinging  lever  under  this  gun,  while  it  had  the  advantage 
of  giving  great  smoothness  of  operation  and  exceptional  reliability 
Co  rhe  action,  had  the  very  obvious  disadvantage  of  being  quite  in 
the  way.  Marlin  therefore  did  away  with  this  lever,  and  subscicuced 
a straight  line  piston.  This  became  a very  difficult  feat  of  engineering 
indeed.  The  piston,  instead  of  giving  a slow  and  accelerating  back- 
ward thrust  through  a connccrint  rod,  wa.s  slapped  back  at  maximum 
-speed  right  at  the  beginning  of  its  stroke,  with  the  result  that  as 
often  ns  not,  it  simply  tore  the  heads  off  the  cartridges  instead  of 
extracting  them.  One  thing  that  was  done  to  modify  this  action  was 
to  add  a sizeable  weight  to  the  piston,  which  slowed  up  ihc  initial 
rearward  motion. 

Another  difficulty  was  that  the  final  closing  motion,  w^hich  with 
the  swinging  lever,  acting  through  a connect  mg  rod,  had  been  slow 
bur  powerful,  now  became  a simple  and  terrific  slam,  which  drove 
the  cartridges  in  so  fast  that  they  were  resized  enough  ro  make  them 
too  shore  for  the  chamber,  and  thus  give  the  effect  of  excess  hcad- 
.spacc.  I'o  counteract  this  effect,  the  chamber  was  made  ii  thou- 
sandths of  an  inch  shorter  than  standard. 


The  work  of  making  this  redesign  was  done  principally  liy  Mr. 
\.  W.  Swehilius,  who  accomplished  a most  difficult  task  in  a few 
weeks,  and  produced  a gun  that  was  used  throughout  the  war  as 
the  principal  synchronized  gun  of  the  U.  S.  air  force,  and  was  also 
used  in  ranks. 

The  Marlin  Gun  was  discontinued  at  the  end  of  World  War  I, 
and  with  its  disappearance  the  old  Browning  Colt  Machine  Gun 
made  its  final  bow. 


The  H^chkiss  Machine  Gun 

It  was  about  the  liine  that  Mr.  Browning  was  doing  his  first  work 
on  the  Colt  Machine  Gun  that  an  Austrian  Army  Officer,  Baron 
\^on  Odkolek,  also  invented  a gas  operated  gun.  I'hcrc  was  this 
difference,  however;  instead  of  using  a swinging  lever,  he  employed 
a simple  reciprocating  piston,  and  overcame  hk  extraction  difficulties, 
ere.,  by  making  the  parts  heavy  and  massive. 

The  heating  problem  was  attacked  by  the  use  of  very  heavy  barrels 
which  would  heat  up  slowly;  moreover,  titc  barrels  were  made  so 


Machine  Guns  ani>  Their  I)i.vki.oi»mem’ 


83 

that  they  could  be  changed  id  an  instant,  even  while  hot.  The  danger 
of  '^cooking  olT”  a cartridge  in  the  hot  harre!  wa?  overcome  by  so 
arranging  the  mechanism  thai  when  rhe  trigger  was  released*  the 
brccch  remained  open,  w'ith  no  cartridge  in  the  chamber. 


Marlin  tank  macbioc  rw  ol  World  W'ar  I shown  mokintcii  in  a unk  uf  ihat 
pcciixl.  This  was  die  Marlin  ainrah  ^im  fiucd  wiUi  a hand  trigger  and  an 
uluminum  radiator  on  (he  barrel. 


Instead  of  feeding  tlie  cartridges  from  l>elcs,  as  do  the  Maxim, 
Coir  and  Browning  (hins,  the  Hotchkiss  feeds  them  from  steel  or 
bras'v  strips  holding  ;r>  cartridges  each.  The  cartridges  arc  held  in 
place  by  spring  fingers  from  which  they  are  stripped  by  the  brccch 
block  as  it  goes  fonvarcl.  When  the  gun  is  operated,  these  strips  can 
be  fed  in  one  after  the  other  without  internipting  the  firing. 

The  gun  gets  its  name  from  the  fact  chat  the  Odkolek  invention 
was  perfected  and  put  into  manufacture  bv  Mr.  Ben  B.  Hotchkiss, 
an  American  living  in  Paris.  The  Hotchkiss  Company  founded  bv 
him  became  one  of  the  major  factors  among  the  armament  makers 
of  the  world.  The  gun  >vas  adopted  by  the  French  Armv’  in  1905* 
and  lias  been  used  bv  them  ever  since.  Hotchkiss  machine  guns  of 
one  model  or  another  became  the  standard  armament  of  many  nations, 
and  have  been  noted  for  their  ruggedness  and  reliability. 


The  Marlin  aircraft  machine  gun  of  World  War  1.  This  was  developed  from  die  old  Browning  designed  Coll  machine  gun  b>  Mr 
A.  W.  Swvbilius  of  the  Marlin  Rockss'cM  Co.  The  pun  used  as  a fixed  aircraft  machine  pun  MDchronized  lo  hre  through  the  pro* 
pellcrs.  It  is  shown  on  the  iripixl  merely  for  convenience  ia  photographing. 


Maciiine  Gcns  and  Their  Devetopment 


«5 

During  World  War  I,  when  we  liad  almost  no  machine  guns  of 
our  own,  our  early  divisions  in  France  were  armed  with  the  French 
Hotchkiss,  Model  of  1914,  using  the  Hmm  Lebd  cartridge,  and  these 
guns  gave  a splendid  account  of  themselves  in  action  and  were  very 
popular  with  our  troops.  During  World  War  II,  the  Standard  Jap- 
anese heavy  machine  gun  was  a Hotchkiss  called  the  Model  92  (1952). 
•Model  92  refers  to  the  \ c.ir  2592  since  the  founding  the  Japanese 


The  Hotchkiss  machin«  gun;  an  old  re  liable  pcrlormer  ot  World  War  I,  used 
by  many  uf  our  divisions  io  Tranie  in  1918. 


f'aiipirc,  which  occurred  years  before  Hie  hcgiiming  of  the 

Christinti  Kra;  hence  their  year  2592  is  uiir  1952.  For  a fuller  ex- 
phmation  of  the  rather  complicated  sv!>tcm  of  model  chronology 
used  by  ilie  Japanese,  see  the  note  in  Random  Notes. 

The  SchivarzJose  Afachme  Gun 

A heavv  machine  gun  xvhich  was  prominent  before  and  durin<^ 
World  War  I,  and  was  even  used  to  a considerable  extent  in  the 
late  war,  was  the  Schwarzlose,  Model  1907/1912,  designed  by  the 
Austrian,  Andrea  Schwarzlosc.  It  has  a retarded  blow-back  mechanism 
whiclr  has  already  been  described  under  ‘'.Mechanical  Principles.” 
It  was  adopted  by  Austria  and  several  other  countries,  and  was  used 
very  extensively  during  the  war  of  19 14-79 iK.  Durintr  that  period 
the  Italians  captured  a mimber  of  these  guns  from  the  Austrians, 


Schwarzloffc  Machine  Gun,  M 190'/19]2.  This  wa\  ihe  5iandard  heavy  machine  of  Au$tria<Hungaf>  before  and  during  World 
War  I.  1(  wa>  also  used  by  several  other  European  nations.  During  >Xor{d  VC'ar  II  Italy  med  large  numbers  of  these  guns  that  they  had 
captured  from  the  Austrians  during  the  previous  World  War. 


Dutch  Indies  short'harrelcd  Madsen  captured  by  the  Japanese 


4 

» **^f 

^ • 21 

4^EI9Sv^  ^ 

♦,a  s^p 

88 


Hatcher’s  Notebook 


and  chese  were  ujied  to  some  extent  during  World  War  II,  and  hence 
have  again  conic  into  public  notice. 


Tke  Madsen  Machine  Gnn 

About  1903  there  appeared  on  the  scene  a machine  gun  which  was 
very  )inich  lighter  and  more  portable  than  any  full  automatic  gun 
had  been  before  theit  time,  and  which  wa.s  rcallv  the  first  of  the 
Machine  Rifle  class  that  became  so  popular  during  World  War  1. 


Mudacu  Madimc  Oun.  The  phoip  taken  ai  SpringtidJ  Armory  about 
at  the  time  of  ihe  tests  which  resulted  io  the  adopm>n  of  the  nenec-Mcrdc 
Automatic  Machine  Kirte,  Model  of  1909. 


I his  was  the  21  pound  recoil  operated,  air  cooled,  magazine  fed 
Madsen  gun,  invented  by  Captain  Madsen  nf  the  Danish  Army. 

The  Madsen  was  tested  in  this  county  about  n/ig,  but  was  passed 
over  in  favor  of  rhe  Light  Hotchkiss,  reseed  at  the  same  time,  and 
adopted  as  the  Automatic  Machine  Rifle  Cal.  .30,  Model  of  1909- 

In  spite  of  the  fact  that  this  gun  was  not  successful  in  the  U-  S. 
Army  trials,  it  was  adopted  and  used  with  great  success  by  several 
nations,  including  Denmark  and  Hoi  bad.  It  was  used  to  some  extent 
iu  Germany,  and  after  World  War  I.  it  was  for  a time  seriously 
considered  by  Great  Britain  as  a successor  to  the  Lewis,  but  flnallv 
gave  way  to  tlic  Bren,  which  was  adonted  instead. 


MaCHI.NE  Guns  and  ThPIR  DfiVELOPMENT 


The  Benet-Mercie  Qun 

Our  first  standard  machine  gun  of  the  automatic  type,  as  compared 
CO  the  hand  operated  type  like  the  Gatling,  was  the  Colt  Automatic 
Machine  Gun,  Model  of  1895.  Note  the  word  “Automadc  ' in  the 
name.  That  was  put  in  to  distinguish  this  new  ty^pc  of  gun  from  the 
simple  “machine  guns'*  like  the  Nordenfeic  or  the  Gatling,  which 
did  not  supply  their  own  power. 

Our  second  standard  machine  gun  was  the  Maxim  Automatic 
Machine  Gvin,  Model  of  J904.  Both  these  were  heavy  guns,  mounted 
on  tripods.  Our  next  standard  machine  gun  was  of  an  entirely  dif- 
ferent type,  which  today  would  be  known  as  a light  machine  gun, 
but  in  those  days  was  called  a Machine  Ride.  It  w’as  the  light  flocch' 
kiss,  designed  by  Benet,  son  of  an  American  Chief  of  Ordnance  who 
had  gone  to  Paris  and  become  an  engineer  with  Hotchkiss,  in  col- 
laboration with  another  Hotchkiss  engineer  named  Mercic.  'This 
gun  was  adopted  by  our  Army  in  1909  after  extended  trials,  and 
was  called  the  Automatic  Machine  Rifle,  Caliber  .p,  Model  of  1909. 

Now  if  at  chat  time  we  had  known  the  least  thing  about  the  tactical 
role  of  machine  guns,  we  would  have  realized  that  we  ought  to  have 
had  two  kinds  in  the  Army  at  the  same  time;  the  heavy  type  for 
one  kind  of  action,  and  the  light  type,  for  a totally  different  use. 
\Vc  didn*c,  however,  realize  this  or  anything  else  much  about  these 
matters,  so  wc  adopted  this  light  gun  as  THE  machine  gun  of  the 
Army.  In  chose  days  cvciy  regiment  had  a machine  gun  platoon, 
made  np  by  detailing  men  from  regular  companies  for  temporary 
duty  in  tlie  machine  gun  platoon.  This  platoon  had  four  guns.  It 
wasn’t  a regular  authori/.eci  company,  but  just  a scraped  together 
^ggtcgfltiun  of  the  men  who  could  best  be  spared  from  other  places. 
Many  times  the  temptation  to  get  rid  of  unw'anted  problem  children 
was  solved  by  company  commanders  by  sending  them  to  the  machine 
gun  platoon.  A pretty^  sorry  outfit  it  w'as,  as  a rule. 

When  wc  had  gone  through  all  these  trials  and  had  finally  settled 
on  the  gun  wc  wanted,  and  had  adopted  it,  wc  gave  the  Hotchkiss 
Company  an  order  for  twenty-nine  of  these  guns.  I repeat,  tv:enty- 
time  only  of  these  guns  at  a time  when  nations  like  Germany  were 
buying  thousands  of  machine  gnas.  The  reason  was  that  the  funds 
allowed  tlie  army  in  those  days  would  pay  for  cweacy-iiine  guns  and 
no  more,  so  we  got  twenty-nine. 

Then  wc  put  the  gun  into  manufacture  at  both  the  Colt’s  Patent 
Fire  Arms  Manufacturing  Co.,  and  at  Springfield  Armory,  and  in 
rhe  next  few  years,  wc  jnadc  a total  of  <>70  of  these  Benct-.Mcrcic 
guns.  That  many,  divided  between  two  factories  was  not  enough 
f<ir  either  of  them  to  leam  and  overctmic  the  usual  production  and 
lieac  creating  difficulries. 


rhe  Automatic  Machint;  Rifle,  Caliber  .50,  Mode)  ol  1909.  whiib  was  ihe  standard  light  machine  gun  of  our  Army  at  the  beginning 
uf  World  War  1.  This  light  Hotchkiss  gun.  known  also  as  the  Benet'Merde,  from  the  names  of  two  Hotchkiss  Coai)>any  engineers  who 
developed  it,  was  superseded  by  the  Browning  Automatic  Rifle. 


Maciiikf.  Guns  and  Ihlir  Dkvi:ix>i»M£N  r 91 

This  Bcnct-Mcrcie  gun  remained  standard  from  i9o<;  until  1916, 
when  the  Vickers  was  adopted  as  a result  of  another  sec  of  tests 
and  trials, 

The  Le^ivis  Machine  Gun. 

Beginning  in  19 ti,  and  at  intervals  thereafter  the  Armv  tested  a 
machine  gun  invented  by  Col.  1.  N.  Lewis,  Coast  Artillery,  U.  S. 
Army.  This  gun  resembled  the  Hotchkiss  in  that  it  was  gas  operated, 
and  employed  a straight  piston  which  svas  driven  to  the  rear  bv  a jet 
of  gas  troni  a port  drilled  in  the  barrel.  'Lhc  cartridge  feed  was  from 
flat  pan  shaped  magazines  holding  47  shots  each,  or  later,  in  the  air- 
craft type,  97  shots.  This  was  placed  on  top  of  the  receiver,  and  was 
fed  around  and  around  like  a cog  wheel  as  the  firing  progressed. 

The  barrel  of  die  gun  was  surrounded  by  an  aluminum  radiator, 
outside  0/  which  was  a sheet  steel  casing  something  like  a section  of 
stove-pipe.  This  casing  was  open  at  the  rear  end,  and  at  the  front  it 
extended  past  the  muzzle  of  the  gun  so  that  ihc  blast  of  gas  from  each 
shot  had  a tendency  to  create  a draft  of  air  through  the  steel  casing 
over  the  aluminum  radiator  around  the  barrel,  thus  keeping  the 
barrel  reasonably  cool  as  firing  progressed. 

In  the  first  .several  tests  of  the  Lewis  gun,  it  failed  to  handle  our 
powerful  .^o*'o6  cartridge  successfully*  and  while  further  develop 
ment  was  under  way.  the  world  War  1 broke  out  in  Europe.  Lewis 
siihmiitcd  hi.s  gun  to  the  British,  and  with  the  relatively  low  powered 
cartridge  it  irtade  a much  better  performance  than  it  did  w'itli 
our  heavy  high-pressure  ainmuniiion. 

In  England  this  gun  was  made  by  the  Birmingham  Small  Arms 
Co.,  as  the  Model  of  1915,  and  it  was  used  with  great  effect  by  the 
British  from  that  year  until  the  end  of  World  War  I. 

In  this  country  a high  pressure  publicity  campaign  was  started  to 
force  our  Army  to  adopt  this  gun.  Repeated  tests,  however,  did  not 
produce  a l^ewis  gun  that  would  satisfacc«>rilv  shoot  our  aimminition. 

In  April.  19 1 6,  the  Armv  held  a formal  lest  to  select  a new  machine 
gun  as  a standard  to  replace  the  Renct-Mcrcie.  The  Lewis  gim. 
made  in  this  country  fur  the  British  l>v  the  Savage  Arms  Donipanv, 
was  naturally  a strong  contender  in  these  tests,  and  the  proponents 
of  this  gun  made  the  most  of  the  reputation  which  ihis  gun  had 
made  for  itself  in  the  British  Service,  and  accused  the  U.  S.  Armv 
of  the  worst  kind  of  reactionary  stupidity  for  allowing  an  American 
invention  to  go  unappreciated  at  home,  only  to  be  adopced  abroad. 

The  face  that  the  gun  had  repeatedly  failed  in  tests  with  our  ammuni- 
tion v\  as  of  course  not  mentioned,  or  was  even  denied. 

In  these  April  tests  of  19x6,  a Lewis  gun  was  submicted  for  the 
U.  S.  amnninicion  which  finally  put  up  a creilitable  performance  and 
showed  great  promise  of  being  capable  of  further  development  to 
handle  our  aniinunition  with  complete  satisfaction.  In  the  test,  this 


Lewis  Machine  Gun,  Model  of  19 1",  lliis  wa$  the  gfound  <>pe  Lewis  gun  which  (he  Army  and  Navy  purchased  at  (he  beginning 
of  World  War  I.  The  Army  boughe  25<X),  and  (he  Na%y  and  Marines  9270.  Afiet  (his  initial  purchase  the  entire  produedon  of  the 
factory  was  devoted  to  the  Lewis  Aircraft  machine  gun.  of  whidi  the  Army  bought  some  47,000, 


Machine  Guns  and  Thfir  Development 


93 


new  Lewis  gun  jammed  206  dmes,  had  35  pares  broken,  and  had 
t5  other  pares  which  bent  or  got  out  of  shape  so  chat  they  had  to 
be  replaced.  This  was  during  the  firing  of  the  20,000  shots  which 
comprised  the  endurance  test  given  machine  guns  in  the  usual  Army 
trials. 

In  this  test  there  was  also  the  Vickci's  gnn,  which  had  no  parts 
broken,  and  none  that  had  to  be  replaced,  and  suffered  only  23 
jams  as  against  206  for  the  Lewis.  Namrallv  this  Vickers  won  the 
test  over  the  l,cwis,  and  was  adopted  as  the  Auunnaiic  .Machine  Gun, 
Caliber  ,30,  Model  of  J916. 

In  this  same  month  of  April,  1916,  there  occurred  an  incident  that 
touched  off  a renewed  and  redoubled  campaign  of  villificacion  of  the 
Ordnance  Department  and  of  the  Army.  The  town  of  Columbus, 
in  New  Mexico.  \sas  raided  bv  a bandit  named  Pancho  N'illa,  and  in 
this  raid  some  civilians  ami  soldiers  w'crc  killed.  It  happened  that  this 
town  was  gar  rise  ne<i  by  a cavalrj'  troop  and  a machine  gun  platoon, 
and  there  were  four  Benci-.Mcrcie  guns  available.  The  raid  was  in 
a way  a miniature  Pearl  Harbor  as  far  a\  the  surprise  element  was 
concerned;  there  did  not  seem  to  be  anv  reason  to  anriripare  any  such 
occurrence,  and  the  little  garrison  was  caught  completely  off  guard. 

The  members  of  the  machine  gun  platoon,  routed  from  their  beds 
in  the  middle  of  the  night,  hauled  out  their  guns  in  the  dark,  bunred 
for  the  ammunition,  and  in  .some  wav  got  the  guns  ro  shooting. 

I'hc  following  is  quoted  from  an  article  that  I wTote  for  the 
Sarur<!ay  Lvening  l^osr  in  the  issue  of  Nov.  10,  1917  “The  night 
wiis  dark,  and  naturally  some  trouble  was  experienced  with  the  guns. 
Occasional  jams  nreurred;  but  in  each  case  the  trouble  w^as  overcome 
and  the  guns  continued  in  the  fight.  At  least  two  of  the  four  guns 
were  alw'ays  in  action.  These  guns  were  not  always  firing,  though, 
as  chev  frequently  had  to  .‘^top  for  lack  of  a suitable  target. 

To  fire  machine  guns  in  the  dark  streets  of  a town  without  a well- 
defined  target  is  co  risk  killing  friend  as  well  as  foe. 

There  were  many  highly  excited  people  present,  however,  and  to 
these  it  no  doubt  seemed  that  all  the  guns  should  be  firing,  regardless 
of  whether  an  cnemv  was  in  sight  or  not.  Thus  it  happened  that  a 
report  was  started  that  the  machine  guns  at  Columbus  had  jammed, 
<md  the  Impression  was  created  that  they  had  not  figured  in  the 
fight.  This  impression  was  false,  for  the  machine  guns  were  a decisive 
factor  in  saving  the  town;  and  in  spite  of  occasional  jams,  they  fired 
nearly  20.000  rounds  of  aJiiiiiunition  in  the  fi<;ht.’* 

After  this  incident,  General  Pershing  was  sent  on  an  expedition  for 
the  capture  of  Villa,  and  the  Regular  Amiy  and  the  National  Guard 
were  mobilized  along  the  Mexican  Border.  The  old  orphan  machine 
gun  platoon  was  done  away  with,  and  each  regime  nr  was  given  a 
itjachine  gun  company  with  four  guns.  Tlic  machine  gun  company 
thus  had  its  own  tables  of  organization,  t\*ith  officers,  non-coms,  etc,, 


Machine  Guns  and  Tueir  DEvr.f,oi>MEKT  95 

and  che  system  of  making  the  machine  gun  outfit  a catch-all  for 
undesirables  came  to  an  end. 

The  Ordnance  Department,  lacking  enough  guns  to  arm  the  newly 
organized  companies  for  all  the  bord^  regiments  made  an  emergency 
purchase  of  350  Lewis  Machine  Guns  from  the  Savage  Arms  Co. 
These  were  for  the  .303  British  ammunirion,  as  the  gun  for  our  own 
high  powered  ammunition  had  not  yet  been  perfected  and  put  into 
production.  We  of  course  had  to  buy  ammunition  as  well  as  guns, 
and  Ford  trucks  were  also  bought  to  act  as  machine  gun  cars.  Up 
to  this  time  all  machine  guns  had  been  packed  on  mules,  so  this  was 
<jiiite  an  innovation  for  that  day. 

1‘he  Ordnance  Department,  of  course,  had  nothing  to  do  with  the 
training  of  soldiers  in  how  to  use  the  guns.  The  guns  and  amiminition 
were  furnished  by  the  Ordnance,  together  with  handbooks  on  how 
ro  operate  the  guns,  hut  the  actual  training  of  the  combat  troops 
was  not  an  Oranance  fiincoon.  This  was  done  by  the  School  of 
Musketry  at  Fort  Silt.  Unfommarely,  there  was  never  enough  of 
an  ammunition  allowance  to  perniic  that  organization  fo  mdufcc  in 
sufficient  function  firing  to  give  the  gunners  faTiiiliarity  with  tlic 
mechanical  operation  of  their  weapons.  The  result  was  just  the  same 
as  a flying  school  would  have  in  training  pilots  without  any  gasoline. 
Much  attention  was  given  to  the  tactics,  and  to  the  theory  of  how 
to  use  the  guns,  but  no  one  actually  knew  how  to  keep  them  firing. 

General  Crozier,  che  Chief  of  Ordnance,  w'as  a powerful  and 
determined  man,  and  he  decided  forthwith  that  the  gunners  should 
have  training  that  would  eliminate  the  talk  of  machine  guns  that  jam, 
and  that  if  the  people  who  should  give  this  training  were  not  doing 
it,  he  would  do  ic  himself,  whether  they  liked  ir  jjr  not.  JIc  rhercforc 
gave  me  instructions  to  accompany  this  shipment  of  350  l.ewis  .303 
Machine  guns,  and  co  go  to  each  organization  which  was  armed  with 
this  gun  and  teach  them  how  to  use  che  guns,  and  thus  prevent  the 
guns  from  getting  an  undeservedly  bad  name.  It  is  rarher  ironical 
chat  che  first  gun  whose  reputation  he  thus  undercook  ro  guard  was 
the  Lewis,  whose  backers  were  already  carrying  on  a publicity 
campaign  to  the  effect  that  this  gun  \va.s  the  only  one  that  woiiIdn‘i 
jam. 

After  a lot  of  fine  instruction  and  many  spectacular  demonstrations 
from  the  Lewis  people  on  the  virtues  of  their  gun,  1 wenr  from 
regiment  to  regiment  along  the  border,  giving  intensive  instnictiDU 
in  just  how  to  get  the  besc  performance,  and  how  to  avoid  rrcuibk. 


French  St.  Etienne  machine  gun  of  World  War  1.  Ji  is  a gas  operated  air 
cooled  macltine  gun,  using  the  30- shot  Ilotdikiss  feed  strips.  It  has  several  rK>vcl 
features  such  as  the  front  sight  with  a compeosauiig  medianism  to  change  the 
sight  elevation  as  the  gun  barrel  beats  up.  The  gas  piston  1$  blown  forward 
instead  of  backward  as  is  ttsuai  in  guns  of  this  kind. 


Th«  Moore  uncrifui^al  machine  fur,  up  for  ie$c  at  ibc  U*  S.  Bureau  of  5tamJarJ»  at  the  time  of  World  Wat  f. 

The  grooved  rotor  via*  driven  at  higii  speed  b>  a powerful  eleciftc  motor.  Steel  ball  hearings  wore  fed  Into  the  center  of  rotor  through 
the  flexible  pipe,  and  were  delivered  at  a speed  of  alnmt  1200  f^.  through  the  dot  at  left.  The  accurac>  was  extremely  poor,  but  the 
invenior  insisted  that  the  gun  csuuld  be  useful  in  the  trench  warfare  un  like  Western  From  of  19 IK.  The  gun  wav  not  used. 


MACirtNE  Guns  and  Tmeir  Deveix)pment 


97 


In  doing  this  I expended  large  quantities  of  ammunition,  as  I believed 
that  the  only  way  to  leam  how  to  shoot  a gun  is  to  shoot  it.  On 
this  job  I was  accompanied  by  Col.  John  J.  Dooley,  of  the  National 
Guard,  Stare  of  Maine,  retired,  who  was  employed  as  an  expert  by 
Savage  Arms  Co. 

] had  received  intensive  indoctrination  on  the  Lewis,  and  everyone 
I saw  praised  it  and  condcjimed  all  the  others,  so  that  knowing 
nothing  about  the  other  guns,  I was  inclined  ro  believe  tlie  propaganda 
chat  I had  been  reading  about  how  bad  the  ocher  guns  were  in 
comparison. 

After  all  the  350  Lewis  guns  had  been  distributed,  I w as  directed  to 
see  up  a school  and  teach  all  machine  gunners  on  the  border,  no 
niacter  what  gun  they  hath  bow  ro  use  their  guns.  At  Harlingen, 
I'cxas,  near  the  mouth  of  the  Rio  Grande,  there  was  a newly  esrai) 
lished  Ordnance  Depot  commanded  by  Optain  Kvcrcrc  S.  Hughes, 
now  Major  General,  Chief  of  Ordnance,  flcrc  1 ser  up  a school  for 
instruction  in  the  Colt,  the  Maxim,  the  Bcncr,  and  rhe  Lewis. 

I soon  found,  much  to  my  surprise  and  chagrin,  rlvac  every  one  of 
the  other  three  was  a far  better  and  more  reliable  gim  than  tlic  Lewis 
I had  been  praising  so  highly.  The  Lewhs  had  some  parrs  that  broke 
and  others  that  bent  caalv’,  and  after  a few  hundred  miles  of  being 
carried  around  in  those  Ford  trucks,  the  gun  w'as  loose  at  the  joints, 
rhe  maga/Jne  rims  were  deformed  so  that  they  would  skip  shots,  and 
the  feed  fingers  that  guided  the  cartridges  in  to  rhe  feedway  would 
bend  and  cause  jams;  etc.,  etc.  In  short,  it  was  just  about  impossible 
ro  keep  these  guns  in  firing  condition.  The  other  three  were  strong, 
rugged,  well  tempered,  and  would  stay  in  shape  indefinitely  if  not 
abused. 

In  the  school  everyone  in  the  companv,  from  Captain  rr>  cook.s, 
had  to  learn  how  to  keep  the  guns  going  under  cvxrv  kind  of  adverse 
condition.  The  course  lasted  two  weeks;  during  rhe  first  part,  the 
reason  for  everv  part  and  how  it  worked  was  explained,  also  what 
troubles  could  happen.  Then  everyone  had  days  and  days  of  actual 
firing.  First  the  gun  would  be  fired  in  good  condition;  afterward, 
a bad  part  would  be  put  ir,  and  the  firer  would  be  given  ammunition, 
and  when  rhe  g\in  misbehaved,  he  was  given  all  the  rime  he  wanted 
to  find  out  the  trouble  and  fix  it.  It  was  aiiiaring  what  a difference 
chat  two  weeks  would  make  in  a company. 

Typical  is  the  case  of  a captain  who  wrote  to  the  Chief  of  Ord- 
nance celling  him  chat  his  Benct-Mercic  guns  wca*  uncrlv  worthless, 
and  asking  to  have  them  exchanged  for  the  new  i.ewis  gun.  Wlicii 
he  came  in  for  his  course,  I told  him  that  he  could  have  his  guns 
exchanged  for  any  of  the  other  three  kinds,  but  that  first  he  would 
have  to  cake  the  two  weeks  course  with  all  four  kinds. 

He  was  dissatisfied  with  this;  wanted  to  change  immediately.  Said 
he  had  been  using  his  guns  four  years,  and  had  never  been  able  to 


Hatcher’s  Notebook 


98 

get  more  than  mo  shots  out  of  any  gun  without  a jam.  1 said  that 
we  would  make  the  exchange,  but  first  I wanted  him  to  lire  each 
of  his  four  guns  300  shots  just  to  sec  how  they  worked.  That  really 
gave  him  a laugh.  He  assured  me  that  no  one  could  get  any  of  his 
guns  to  shoot  more  than  two  shots. 

His  guns  were  placed  on  a table,  and  he  was  told  to  have  his  men 
gather  around  and  pay  close  attention  as  wc  were  going  to  explain  the 
function  of  each  piece.  My  assistants  and  1 then  rook  the  guns  to 
pieces,  and  explained  just  how  each  piece  worked,  but  at  the  same 
lime  casually  pointed  out  some  defects.  We  would  say,  for  example, 
“Now  the  firing  pin  must  have  a good  rounded  point,  so  that  it 
will  indent  the  primer  properly  without  puncturing  it.  This  firing 
pin  has  no  point  at  all.  Naturally  rhe  giiii  would  nor  fire  in  that 
condition,  so  let’s  puc  in  this  new  firing  pin.  On  this  otlier  gun 
the  actuator  is  badly  bent— see,  right  here.  That  will  keep  the  breech 
block  from  dosing  and  of  course  the  gun  will  not  fire,  let’s  replace 
that  bent  part  with  a new  one.”  By  the  time  the  guns  had  been 
pur  together  again,  the  had  pans  had  been  replaced.  Also,  the  Captain 
was  doing  a bit  of  thinking,  no  doubt. 

Wc  then  had  his  own  gunners  load  rhe  gun,  but  two  of  them 
started  ro  puc  the  feed  scrips  in  wrong.  There  is  a little  trick  to 
loading,  if  it  is  done  wrong,  the  gun  will  fire  just  two  shots  and 
then  jam.  This  is  all  explained  in  the  instructions,  hut  nobody  had 
read  them,  it  seems.  So  his  gunners  fired  three  hundred  shots  each, 
with  no  jams  or  trouble  of  any  kind.  TIk  Captain  said  that  he  just 
wouldn't  have  believed  it;  he  said  he  saw  that  there  was  a lot  to 
kam  about  this  business. 

After  he  had  completed  his  two  weeks  he  was  asked  which  of 
the  three  other  makes  uf  gun  he  wanted  in  exchange  for  his.  He 
said  ‘TJo  one  is  going  to  get  chose  guns  away  from  jiie;  they  arc 
the  best  guns  in  the  world,  and  Tm  going  to  sic  right  duwn  and  write 
Co  the  Chief  of  Ordnance  and  tell  him  so.”  And  he  did:  I saw  the 
letter  afterward  in  Washington. 

During  the  nine  months  that  this  school  ran,  k trained  one  com- 
pany Q week;  it  was  a two  weeks  course,  but  there  were  nvo  com- 
panies present  all  the  time,  one  taking  the  first  week,  of  mechaiiical 
instruction,  the  ocher  taking  the  second  week,  of  actual  firing.  The 
men  that  were  trained  in  this  border  school  and  one  that  I later  ran 
at  Sandy  Hook  for  all  the  young  r^ular  Ordnance  officers  and  at 
Springfield  Armory  for  reserve  officers  and  emergency  officers 
became  the  key  machine  gun  men  in  the  entire  Army  during 
World  War  I. 

This  school  kept  going  until  the  first  of  April,  IQ17,  when  war 
with  Germany  seemed  imminent,  and  1 received  a telegram  ordering 
handle  our  ammunition  with  complete  satisfaction.  In  the  test,  this 


Machine  Grxs  and  Their  Dfvri.oi*mi:vt 


99 


The  Berth  icr  m a chine  tifle  suboiitied  for  lest  in  I')  1 7.  Ii  pas*.ed  an  excel]  cm 
lest,  but  ^is  noi  adopted,  39  (he  Browning  ihcn  being  ]>ui  into  production. 
The  officer  II  ring  the  gun  is  the  present  author. 


mv  notes  there  is  an  nlti  Ordnance  Ollicc  memo  sheer  on  which  I 

4 

have  written;  “W’.ii  Declared;  on  hand  6-0  Rcnct,  zHz  Maxim,  145 
Coll,  55 j Lewis/’  Believe  it  or  nor,  (hose  liaurcs  rc|>rescnt  all  the 
machine  guns  this  great  nation  owned  when  we  w ent  lo  war  with 
Germany  in  1917.  None  of  the  new  \'ic leers  had  vec  been  delivered. 

A little  further  down  on  chat  memo  is  the  entry;  ‘'April  12;  1500 
Lew' is  Guns  Ordered/’  It  seems  that  while  all  this  border  instruction 


ih^  Hrowniaff  .50  caliber  iriacbine  gun,  made  bv  <'nlt 


Machikt:  Guns  and  Their  Development 


lOI 


Th«  Hrowninp  .30  caliber  wacer  machine  gun. 


had  been  going  on,  the  Savage  Anas  (Company  had  been  piTfecting 
the  Lewis  for  our  aniimmition,  and  we  ordered  these  1300  without 
a formal  trial.  We  really  needed  guns  by  then. 

In  Alay  19171  the  War  Ji)epartmcnt  held  a machine  gun  test  before 
a board  composed  of  Army  officers,  Navy  officers,  and  civilians, 
called  the  United  States  .Machine  Gun  Board.  At  this  test  the  Lewis 
gave  a good  account  of  itself,  and  more  were  ordered  by  the  Army 
to  a total  of  2500.  The  Navy  and  Marines  got  9270.  The  Annv  then 
adopted  a stripped  and  lightened  version  of  the  F ewis  as  the  standard 
flexibly  mounted  gun  for  aircraft  use,  and  purchased  47,000  of  them. 
This  Lewis  Aircraft  gun  did  not  have  the  barrel  jacket  or  the 
aluminum  radiator. 

The  Bro'ii^mng  Macbwe  Gun 

A gun  which  gave  a sensational  performance  before  this  United 
States  Machine  Gun  Board  was  a heavy  water  cooled  gun  submitted 


102 


Hatcher’s  Note  hook 


by  Mr.  John  Browning,  of  Ogden,  Urah.  It  was  buiJc  on  die  recoil 
principle,  with  a very  much  simplified  action.  As  it  was  much  easier 
10  manufacture  chan  the  rhen  standard  Vickers,  none  of  which  had 
yet  been  delivered,  it  was  decided  to  concentrate  on  rhe  simpler 
and  more  easily  made  Browning.  The  (Jolt  Co.  which  was  already 
getting  into  production  on  the  Vickers,  produced  9)27  of  the  water 
cooled  type,  and  7502  of  the  aircraft  model  during  the  war,  while 
Westinghousc  and  Remington  produced  71,019  heavy  Browming 
machine  guns  during  World  War  I. 

Ijkc  the  Vickers,  the  Heavy  Browning  is  water  cooled  and  belt 
fed,  [>iit  the  belt  is  of  much  simpler  and  cheaper  construction.  In 
fact,  it  is  exactly  the  same  as  Browning  used  on  his  Colt  Machine 
(iiin  Model  of  1895.  The  weight  of  the  Heavy  Browning  is  36!/; 
pounds  with  water  in  the  jacket,  and  the  tripod  weighs  48  pounds. 
The  rate  of  fire  is  about  550  shots  per  minute. 

The  Browning  machine  gun  with  water  jacket  removed  and  with 
the  barrel  made  heavier  and  sliortcr  was  used  for  arming  tanks,  and 
w'as  also  adapted  cn  ground  use  on  a tripod  as  a light  machine  gun. 
Stripped  of  its  water  jacket  ic  was  used  during  world  War  1 as  a 
synchronized  aircraft  ^n  for  fixed  mouncm^  on  the  aircraft  of  that 
tfay.  firing  through  the  propellers.  Much  improved  and  lightened 
nfr'er  the  war,  and  fitted  with  right  and  left  hand  feed,  it  became  the 
sunulard  .30  caliber  aircraft  machine  gun. 

A similar  series  of  Browning  guns  was  made  up  in  ,50  caliber. 
I liese  are  used  for  both  airci^t  and  ground  use,  and  have  been 
widely  copied  all  over  the  world,  and  were  used  not  only  by  the 
V.  S.,  but  by  many  other  nations  during  World  War  II. 


Light  Machine  Gum 

During  the  early  part  of  the  first  World  War,  the  (term an 5 were 
armed  only  with  the  heavy  Maxim  machine  gun,  and  had  no  light 
machine  gun  to  compare  with  the  British  i.ewis.  These  lighter  guns 
could  readily  be  carried  forward  with  advancing  troops,  and  after 
the  men  had  attained  an  advanced  position,  they  could  lie  flat  with 
these  guns,  and  produce  bands  of  fire  to  stop  a counter  attack. 

1 he  Germans  soon  felt  the  need  for  such  a gun,  and  produced  a 
lightened  version  of  the  Maxim  gun,  known  as  the  ’08/15.  This  was 
simply  a Maxim  with  a smaller  M'atcr  jacket,  and  mounted  on  a bipod 
support  su  chat  ic  could  be  used  in  the  prone  position,  the  same  as 
the  Lewis  could.  Feeding  was  from  100  round  belts  carried  in  small 
boxes  arranged  to  attach  to  the  side  of  the  gun.  This  was  a most 
effective  weapon,  and  produced  many  casualties  among  our  forces. 

Toward  the  end  of  that  war  the  Germans  produced  another  light 
type  of  Maxim,  called  the  ’08/18,  which  was  the  same  as  the  other, 
except  that  the  water  jacket  was  omitted  entirely,  and  a perforated 
barrel  supporting  tube  was  substituted  for  it.  Naturally  the  ability 


Hatcher’s  Notebook 


204 

to  produce  sustained  fire  was  less,  as  the  barrel  would  heat  up  after 
about  a hundred  rounds  so  diat  it  was  too  hoc  to  shoot. 

This  use  of  light  guns  bv  the  British  and  Germans  caused  a need 
for  such  a gun  co  be  acutely  felt  by  the  French,  and  the  result  was 
the  development  of  a new  gun  called  the  ‘^Chauciiat,  ’ weighing  only 
about  25  pounds.  With  this  gun  a new  t\’pc  of  machine  gun  firing 
became  much  talked  of,  and  that  was  the  so-called  “waiting  fire.” 
The  gunner  was  supposed  to  carry  the  gun  forward  with  him  during 


German  Maxixr  machine  gun,  Model  of  1908.  1(  was  the  standard  heavy  uiH' 
chine  gua  of  the  German  Army  in  World  War  I,  and  was  used  as  a reserve  and 
home  defense  weapon  xo  World  War  II, 


Ills  advance,  point  it  in  the  direction  of  the  enemy,  and  fire  it  from 
the  hip.  The  Chauchat  was  a machine  rifie  with  a bipod,  and  was 
of  the  “Long-recoil”  type  mechanism.  The  barrel  and  all  of  the 
breech  mechanism  recoiled  several  inches  to  the  rear  inside  the  barrel 
casing.  'I'hcsc  heavy  parts  moving  backward  and  forw’ard  weighed 
almost  as  nmch  as  rhe  rest  of  the  gun,  and  the  result  was  a violent, 
jerky  motion  of  the  gun  when  tiring.  The  mechanism  was  exude, 
but  it  was  simple,  and  for  this  latter  reason  the  guns  could  be  made 
in  almost  any  fairly  well  equipped  machine  shop.  Many  thousands  of 
them  were  used,  not  only  bv  the  French  but  bv  the  American  Army 
as  well,  those  used  by  the  Americans  being  chambered  for  our  own 
cartridge.  This  gun  was  much  disliked  as  a crude  makeshift,  and  was 
discarded  as  soon  as  possible  after  rfic  war. 


German  Maxim  '08/15  Light  htacbine  Gun.  This  was  the  standard  Light  Machine  Gun  of  the  German  Army  in  the  £cst  World  War, 
and  did  enormous  execution.  It  was  continued  in  use  as  a standard  gun  bv  the  Germans  up  to  about  1956,  and  was  used  to  a considerable 
extent  as  a substitute  in  World  War  II. 


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I'hf  Irenkh  Chauchat  machine  rirte  as  used  by  ihe  American  Arm)  in  1918.  The  gun  shown  was  made  for  use  with  the  8 mm 
dee.  The  scmi-rircular  tna^.x/ine  held  .M>  shots. 


The  Hocchkiss  njHihinc  rifle  suhmiucd  ior  lesi  io  I VI 7.  It  had  in  the  mechjinisni 
.1  clockwork  device  like  (hai  in  an  ekuric  toa&tvr.  lo  keep  it  trom  firing  loo  fast. 
“Walking  Are/'  »hiM)iing  the  gun  from  the  hip.  as  >howu.  while  advancing  across 
the  “Mo  Man's  Land”  of  ihe  1916  trench  warfare  was  a favorite  way  of  using  the 
auto  malic  weapons  of  thar  day. 


The  Brirish  incorrectly  call  this  gun  the  “Chauchard/’ 

The  ias  true  cion  pamphlets  in  French  that  accompimicd  the  8mm 
Chauchat  guns  that  we  used  in  1918  spelled  it  ‘*Chauchac'\  Col.  Calvin 
Goddard,  of  the  Historical  section,  Army  War  College,  traced  the 
word  back  to  its  origin  from  the  name  of  Chauchat.  The  French 
call  it  Model  1915  C.S.R.G.,  from  Chauchat,  Suterre,  Rihey  Rolle 
and  Gladiator,  who  developed  this  gun. 


Machine  Guns  and  Their  Development  109 

The  Aut07natic  Rifie 

Another  gun  chat  Mr.  Browning  submitted  to  the  United  States 
Machine  Gun  Board  in  May,  1917  was  the  Browning  Automatic 
Rifle.  This  gun  was  so  diflferent  in  characteristics  from  the  conven- 
tional Machine  Gun  or  Machine  Rifle  of  the  day  that  it  created  a 
sensation  when  it  was  submitted  to  the  Board.  I was  present,  and 
well  remember  the  excitement  it  produced. 

It  was  the  first  weapon  light  enough  to  be  fired  from  the  shoulder 
and  ac  the  same  time  sufficiently  lieavj'  and  rugged  to  permit  fairly 
long  bursts  of  full  automatic  fire.  It  was  a 15  pound  gun  made  on 
the  lines  of  a large  shoulder  rifle.  It  was  gas  operated,  and  was  fed 
from  detachable  box  magazines  holding  20  shots  each.  Ic  could  be 
arranged  to  deliver  either  full  automatic  fire  or  single  shots  at  will, 
by  changing  the  position  of  a lever  on  the  side  of  the  gun.  It  was 
well  adapted  for  the  marching  fire  in  vogue  during  the  trench  war- 
fare of  chose  days,  as  well  as  for  full  automatic  fire  from  the  prone 
position,  using  any  rest  that  might  be  available  for  the  muzzle  of 
the  gun.  The  action  is  described  on  page  58. 

liiis  gun  can  be  fired  full  automatic  from  the  shoulder,  but  it 
requires  practice  to  do  this  without  losing  control  of  the  gun.  When 
this  is  attempted  by  someone  who  does  not  know  the  trick,  the 
rapid  succession  of  recoils,  coming  at  the  rate  of  450  a inimitc,  will 
i|uickly  throw  the  fircr  off  his  balance,  and  he  will  usually  allow 
the  muzzle  to  swing  around  to  the  right,  or  up  into  the  air,  or  both. 
A serious  tragedy  w^as  narrowly  avoided  at  an  early  demonstration 
of  this  gun  when  an  inexperienced  person  tried  to  fire  it  this  way, 
and  the  muzzle  swept  rapidly  toward  the  group  of  persons  standing 
at  the  fireris  side.  It  is  rcallv  the  surprise  effect  more  than  anything 
else  that  is  responsible,  for  if  the  fircr  >vill  just  lean  heavily  into  the 
rifle  as  he  starts  firing,  this  motion  can  be  controlled. 

Ihis  gun  passed  a magnificent  test  before  the  board,  and  was 
immcdiacclv  adopted,  and  85,277  of  them  were  produced  during  the 
year  and  a half  that  elapsed  before  the  end  of  chat  w^ir.  This  gun, 
ofllcially  called  the  “Browning  Automatic  Rifle,  Model  of  1918,”  but 
more  commonly  known  as  the  BAR,  was  the  standard  weapon  of 
its  type  in  onr  Army  during  World  War  II.  The  Germans  called 
bar’s  captured  from  Poland  the  Maschinengewehr  28  (p),  and  those 
captured  from  Belgium  the  127(b). 

During  the  years  since  its  adoption  there  have  been  several  changes 
or  modifications  to  this  gun.  The  Browning  Automatic  Rifle,  C^l.  .jo, 
M 1918  Af,  which  is  limited  standard  at  this  writing,  has  a gas 
cylinder  with  spiked  feet  attached  to  the  s:as  evlinder  tube  just 
forNvard  of  the  forearm,  and  a hinged  butt  plate  extension  designed 
to  rest  on  top  the  shoulder  of  the  fircr.  The  gas  cylinder  has  been 
changed  to  have  a larger  diameter,  and  to  incorporate  a relief  valve 
in  the  head.  The  forearm  is  shorter,  and  is  cut  away  from  the  barrel. 


Hro«ning  machine  riUc  made  b>*  Fabrique  Naiionalc.  at  Her»ul.  Liege.  Belgium 


1 12 


Hatcher’s  Notebook 


The  M 1918  A2  has  the  forearm  cut  away  even  more,  with  a 
metal  shield  incorporated  to  protect  the  recoil  spring  from  the  heat. 
A bipod  with  skid  type  shoes  is  assembled  co  the  flash  hider  and  a 
stock  rest  is  htted  into  a recess  in  the  buttstock.  This  model  also 
has  a device  for  slowing  the  rate  of  fire  when  desired.  It  also  has 
a hinged  butt  plate  extension,  which  is  shorter  than  that  on  the  Ai. 
The  rear  sight  lias  been  changed  to  include  click  adjustments  for  both 
elevation  and  windage. 

The  Browning  Machine  Rifle,  M 1922  has  a bipod  and  a heavy 
flanged  barrel.  'I  his  modification  of  the  B A R which  was  used  for 
a time  as  a light  machine  gun  has  been  superseded  for  this  use  by 
the  Browning  Machine  Gun,  M 1919  A4,  and  is  now  obsolete. 

I'hosc  nations  which  do  not  use  the  BAR  all  use  some  ocher  gun 
of  similar  characteristics.  L.Kaniples  of  other  guns  on  the  same  general 
principle  or  at  least  of  similar  dimensions  and  designed  for  the  same 
tactical  use  are  the  Rricisli  Bren,  the  French  Chatcllcrault,  the  Japanese 
Year  99  Model,  (M  1959),  the  Mexican  Mendoza,  and  others. 

General  Observations  on  Machine  Guns 

It  w'ill  be  seen  from  what  has  been  written  above  that  machine  guns 
can  be  divided  roughly  into  two  classes,  w^atcr  cooled  and  air  cooled. 

In  the  W'acer  cooled  guns,  whenever  the  irigi^er  is  released  during 
firing,  the  mechanism  stops  with  a live  cartridge  in  the  chamber. 
Most  air  cooled  guns  are  made  so  that  trigger  is  released,  the  gun 
stops  with  the  breech  open  and  the  chamber  empty.  When  the  trigger 
is  again  pulled,  it  releases  the  mechanism,  which  closes,  pushing  in 
a fresh  cartridge  at  the  same  time,  and  fires  as  it  locks.  The  Hotchkiss 
Machine  (iun,  the  Lewis,  the  Bcnct-Mcrcic,  the  Browning  Auto 
inatic  Rifle,  and  most  other  similar  guns  arc  made  in  this  way.  The 
reason  for  this  is  nlwions.  With  an  air-cooled  gun  the  barrel  gets  verv 
hot,  and  if  a live  cartridge  w'erc  left  in  the  barrel  when  the  firing 
w'as  interrupted  it  might  explode  in  a few  seconds  from  the  heat. 

At  a lecture  at  Sandy  Hook  in  the  early  p<art  of  1917,  after  I 
had  just  previously  been  conducting  a series  of  machine  gun  schools 
along  the  Mexican  border,  the  fact  was  mentioned  that  the 
barrel  of  a gun  would  get  red  hoc  wlien  fired  extensively  without 
stopping.  An  official  who  was  present  said  that  it  was  impossible  to 
fire  a gun  that  much  without  a jam.  Accordingly  a demonstration 
was  arranged  for  a class  of  students  who  were  studying  machine 
guns,  and  I personally  fired  a Benet-Mercic  machine  rifle  1*000  shots 
without  stopping.  After  700  shots  the  barrel  was  red  hoc,  and  at  the 
end  of  the  thousand  shots  the  barrel  was  a bright  cheriy  red,  and 
part  of  the  receiver  had  begun  to  glow.  'Lhc  official  who  had  started 
the  argument  was  dancing  up  and  down,  shouting:  “I  see  it  but  1 
don’t  believe  it.” 

Of  course,  in  practice  a barrel  is  never  fired  enough  to  make  k 


Mexican  Mendo/rt  xiiachine  gun.  This  oj>efaie<1,  air  cooled  lighi  machine  gun  weighs  ab<iiu  20  pounds,  and  has  the  barrel  arranged 
that  it  may  be  changed  aiinost  insuntlv  when  hot. 


Japanese  Model  99  (1959)  light  machine  gun.  This  was  the  latest  Japanese  light  machine  gun  to  be  used  in  World  War  II.  It  is 
gas  operated,  weighs  about  Hi  pounds,  and  is  simple  and  effective  in  design. 


French  7.5  imn  Chaiellerauh  machine  |;un  Model  1924>i9. 


The  author,  protected  by  a^he«ioi  gloves,  is  rcmovinp  the  barrel  from  a Coii  machine  gun  during  World 
War  1.  I'hese  air-cooled  guns  heated  up  rapidly  when  iired<  and  a hot  barrel  could  1>e  replaced  with  a cool 

one  AS  ^Knwn. 


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red  hot,  blit  several  hundred  shots  will  make  the  barrel  of  an  air- 
cooled gun  too  hot  for  safety  in  case  of  a jam.  In  working  with  air- 
cooled guns  some  very  CAciting  experiences  will  lie  had  when  a jam 
occurs  with  a very  hot  barrel  and  a cartridge  stuck  in  the  chamber, 
and  with  the  breech  partly  open. 

Once  on  the  jMcxican  border  I saw  a student  get  a cartridge 
jammed  in  a hoc  gun  with  the  breech  partly  open.  He  was  looking 
right  in  it  and  1 had  visions  of  having  the  cartridge  explode  in  his  face, 
so  I snatched  him  away  from  the  gun  and  grabbed  up  a cleaning  rod 
so  as  to  knock  the  hot  cartridge  out  before  it  had  time  to  go  off. 
The  effort  was  just  a little  too  late,  however,  for  as  I shoved  the  rod 
down  the  muzzle,  the  cartridge  went  off.  'I'hls  apparently  lvap|>ened 
just  about  the  time  the  rod  touched  the  bullet,  for  chc  bullet  did  not 
go  out  of  the  barrel.  The  cartridge  case  was  blown  to  bits  but  no 
dajiiagc  was  done,  as  the  breech,  being  open  at  the  back,  allowed  the 
explosion  to  dissipate  itself  to  a large  extent.  I knocked  out  the  bullet 
and  found  that  it  was  somewhat  liactened  where  the  point  had  rested 
against  the  cleaning  rod.  I still  have  this  bullet  and  the  remains  of  this 
cartridge  case  among  my  rather  large  collection  of  cartridge  curios. 

At  the  test  of  the  Berthier  machine  rifle  at  Springfield  Armory  in 
1917,  a jam  occurred,  and  when  the  handle  of  the  gun  was  drawn 
back  the  hot  cartridge  was  ejected  but  exploded  in  the  air  just  in 
front  of  the  group  of  men  who  were  holding  the  gun.  The  bullet 
htuck  in  Che  cuff  of  one  of  the  spectators. 

Another  time  at  Springfield  Armory  a cartridge  exploded  while 
I was  extracting  it  from  a hut  Browning  automatic  rifle,  but  fortun- 
ately it  was  all  the  way  out  of  the  breech;  and  when  a modern 
military  rifle  cartridge  explodes  in  the  open  air  it  does  not  have  much 
force,  so  no  damage  was  done.  Usually  the  explosion  is  just  sufficient 
to  tear  open  the  cartridge  case  and  send  the  bullet  with  very  low 
velocity.  Of  course  there  is  danger  of  getting  pieces  of  brass  blown 
into  hands  or  eyes. 

The  greatest  danger  in  a c*ase  like  this  is  in  having  an  explosion 
when  the  breech  is  jammed  in  a position  very  nearly  dosed.  In  this 
case  the  pres.sure  is  high  and  the  explosion  is  violent,  and  some  parts 
of  the  breech  mcchanisnt  are  likely  to  be  blown  out  with  sufficient 
force  to  do  great  damage.  In  this  way,  an  extractor  blew  out  of 
a Marlin  gun  and  struck  a soldier  in  the  abdomen  inflicting  a wound 
from  which  he  afterward  died. 


Submachine  Gfms  or  Machine  Pistols 
During  World  War  I,  the  Germans  introduced  into  actual  and 
rather  extensive  use  a type  of  machine  gun  which  up  to  that  time 
had  been  very  little  known,  but  which  was  veiy  widely  used  in 
World  War  it.  This  is  the  machine  pistol,  or  submachine  gun,  firing 
pistol  ammunition,  or  in  some  cases,  ammunition  intermediate  in 


The  first  Suhoiarhifie  8*J0;  the  Italian  Villar  Pem*a,  shooting  the  9 dim  ParabeilurD  (Luger)  pistol  cariiidge.  I testetl  this  gun  in  1917. 


The  German  Bergmann  Submachine  of  World  War  I,  called  the  M.P.  (\fasrhinen  Pistole)  18.  It  has  a siraight  blow-back  action 
and  shoots  the  9 mm  Luger  pistol  cartridge  from  a saail  shaped  magazine.  The  World  War  11  submadiine  guns  are  no  advance  over 
this  except  in  cheapness  of  mamifauuce  due  lu  their  fiims>  const  ruction  of  tubing  and  stampings, 


i 

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120 


HATa!£R*5  Notebook 


power  between  pistol  and  rifle  ammunition.  Ir  was  in  1917  that 
my  first  acquainrenance  with  submachine  guns  occurred  in  testing  the 
Italian  Villar  Perosa  gun,  (sometimes  called  the  Revelli).  This  was  a 
two-barrelled  weapon,  shooting  the  9 mm  Luger  pistol  cartridge, 
and  intended  at  that  time  to  be  used  in  arming  airplanes.  There  were 
fifty  cartridges  in  each  of  the  two  magarines,  and  on  pressing  the 
trigger,  they  were  all  fired  in  a little  over  a second,  making  the  speed 
of  the  firing  so  rapid  that  the  sound  of  the  individual  shots  could 
not  be  distinguished  at  all.  The  sound  of  firing  this  gun  was  much 
like  that  of  tearing  a strip  of  canvas. 

During  the  latter  part  of  the  first  World  War,  the  Germans  used 
a number  of  submachine  guns  of  a type  called  the  Bcrgmann.  This 
was  straight  blow-back  gun  used  the  l.iigcr  pistol  ammunition  from  a 
so-called  snail  magazine,  that  is  ”ne  in  which  the  cartridges  lie  in  a 
spiral  or  snail  shaped  drum. 

After  the  end  of  the  fint  World  War,  General  Thompson,  a re- 
tired Army  officer  invented  a submachine  gun  shooting  the  .45 
automatic  pistol  cartridge.  This  weapon,  known  as  the  “Tommy  Gun“ 
became  a favorite  weapon  of  the  gangsters  during  the  prohibition 
era  in  the  United  Scares,  and  in  this  wav  received  much  publicity. 
It  was  adopted  by  the  Army,  ami  was  a standard  weapon  during 
W’orld  War  II. 

Every  nation  chat  fought  in  World  War  II  had  some  kind  of  sub- 
machine gun,  and  some  had  several  varieties.  Owing  to  the  low  pow'cr 
of  the  cartridge  involved,  these  required  no  lucking  device,  and  they 
were  therefore  coascructed  on  the  straight  blow-back  principle.  None 
of  them  showed  any  particular  advance  over  the  original  German 
Bcrgmann  of  World  War  I,  except  in  simpler  magazine  arrangements 
and  cheapening  of  manufacture  by  the  use  of  simple  turned  or 
stamped  out  parts.  Examples  are  the  British  Sten,  the  Australian 
Austen  and  Owen,  the  German  Schmeisser,  etc. 

Col.  Rene  R.  Studler  of  our  Army  contributed  CO  this  field  the 
U.  S.  Submachine  gun  Cal.  .45  M3,  which  was  a real  advance  in  this 
category  of  weapons.  It  is  characterized  by  the  utmost  simplicity  and 
cheapness  of  manufacture.  It  is  made  so  that  by  the  .substitution  of  a 
barrel  and  magazine  together  with  some  other  parts,  it  can  be  almost 
instantaneously  converted  to  shoot  the  9 mm  Luger  or  Parabcllum 
ammunition  almost  universally  used  as  the  pistol  cartridge  by  European 
nations. 

In  1943,  the  Germans  introduced  a so-called  machine  pistol  which 
was  entirely  out  of  the  class  of  the  guns  mentioned  above.  It  was  in 
reality  a full-automatic  carbine,  made  to  shoot  a special  shortened 
vei-sion  of  the  standard  German  7.9  rifle  cartridge.  There  were  several 
models  of  diis  gun,  differinij  only  in  details  called  the  MP  43,  the 
.\tP  43 /j  and  the  MP  44. 


The  Gerfnan  SchoieUscr  9 mm  suhmachtne  gun  MP  40  iisirig  (hf  Parahclluiu  cartridge. 


Auscralun  Owen  Submachine  gun,  Notable  only  lor  one  thing;  utter  cbea|>ness  ol  construction. 


British  Sten  Submadiiue  gun  Mark  II,  Fsseniially  chw  is  the  B ergmann  of  World  War  I thwpened  as  much  as  p4)ssihle 
Bergmann.  u uses  the  9 mm  Luger  cartridge.  On  account  of  it#  atierly  crude  construction  and  its  clumsiness  it  was  usually 
our  soldiers  the  *'S(ench’*  sun. 


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The  Russian  SuJiaev  7.62  mm  machine  pistol  ot  submachine  gun  called  PTS  1943. 


German  MP  44.  This  U a full  aucocnaiic  carbine  shooting  a shortened  version  o(  the  ~.9  riBc  cartridge.  There  were  ilirec  variations 
of  this  w'eapon  which  differed  oniy  io  uuinH>or(aiu  details,  called  the  XfP  45,  the  MP  45/1,  and  the  MP  44. 


126 


H.ATCHER’s  XoTtBOOK 


Machine  Guns  hi  World  War  II 

During  World  War  II,  the  standard  American  ground  cvpe  heavy 
machine  gun  was  the  Browning  in  essentially  the  same  form  as  that 
used  in  the  first  World  War,  and  moiinred  on  the  same  tripod.  It  is 
the  Browning  heavy  belt  fed  water  cooled  machine  gun,  called  the 
M rQi7  A I,  and  the  rripod  is  likewise  die  M H)iy  Ai,  The  only  im- 


Animunnion  for  (he  MP  43  and  MP  44  (left)  compared  with  the 
rcf;u)ar  German  rifle  cartridge  (right)* 


pnrtanc  change  in  the  gun  from  the  original  design  Is  the  strengthen- 
ing of  the  water  jacket  end  cap,  and  an  improvement  of  the  fastening 
of  the  water  jacket  to  the  trunnion  block.  The  receiver  is  also  re- 
inforccci.  The  general  appearance  and  functioning  of  the  gun  remain 
identical. 

I he  light  machine  gun,  called  the  Brown in<j  Machine  Ciun  M iqh; 
A4,  on  ground  tripon  i\l  2,  is  a modification  of  the  Browning  l ank 
Machine  Gun  used  in  World  War  I.  This  gun  has  the  usual  Browning 
mechanism,  but  instead  of  a water  jacket,  it  has  a |.>crforitted  barrel 
jacket  or  support,  and  a rather  hcavv  barrel.  It  is  air  cooled. 

During  the  recem  war,  a whole  series  of  .50  caliber  Browning 
machine  guns  was  ejuploved.  They  were  used  in  both  the  water 
jacketed  and  the  air  cooled  varieties,  for  both  aircraft  and  anti- 
aircraft, In  combat  vehicles  and  tanks,  and  for  other  uses.  The  varieties 
most  used  were:  The  Browning  Machine  Gun,  Caliber  -50,  M 2, 
aircraft,  basic;  an  air  cooled,  recoil  operated,  alternate  feed  gun, 
suited  for  any  type  of  installation  in  aircraft. 

The  Browning  Machine  Gun,  Caliber  .50.  water  cooled,  flexible, 


one 


The  Btb'd  niuihine  gun.  This  was  a heavy  air  cuoied  gas  operated  gun  used  by  the  British  and  (be  Germans  in  armored  vehicles.  The 
shown  in  this  cut  is  che  Czech  version  called  ZB  53. 


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Machine  Guns  and  Tueik  Develo  lament 


129 


type;  a recoil  operated,  water  cooled,  al  tern  arc  feed  gun.  There  is 
a water  chest  with  a puinp  for  supplying  a circulation  of  water 
through  the  jacket.  'Vhis  pennits  firing  long  bursts  without  cooling. 
This  gun  was  used  extenrively  for  anti-aircraft  work. 

The  Browning  Machine  Gun,  Cal.  .50M2,  HB,  fixed  type;  an  air 
cooled,  recoil  operated,  alternate  feed  gun,  adapted  to  fixed  mounting 
in  tanks  or  combat  vehicles. 

The  Browning  Machine  Gun,  Cal.  .50,  M 2,  heavy  barrel,  flexible; 
the  same  as  the  fixed  gun  except  chat  it  has  a spade- grip  back  place 
asscmblv,  and  is  fitted  for  flexible  moimtii^  in  tanks,  combat  vehicles, 
or  on  the  Machine  Gun  Tripod  Mount,  Cal.  .50,  M 3. 

Most  of  the  Allies  of  course  used  .50  caliber  Brownings  furnished 
by  the  United  States.  Great  Britain  ased  the  Bren  as  the  principal 


light  machine  gun,  with  the  Vickers  still  taking  the  heavy  machine 
gun  role.  For  use  in  combat  vehicles,  they  used  the  Besa,  in  7.92 
caliber,  an  almost  exact  copy  of  this  gun  as  originally  made  in  Czecho- 
slovakia, 


The  Germans  also  used  the  Besa,  chough  in  slightly  different  form 
from  that  used  by  the  British.  As  ground  machine  guns  they  used 
light  recoil  operated  guns,  very  similar  in  general  characteristics  to 
the  ’08/18  Vickers  ot  World  War  1,  but  with  smaller  and  lighter 
breech  mechanisnis.  These  gun.s  were  air  cooled  and  belt  fed,  and 
were  developed  from  the  Drevse  MG  13  of  World  War  I.  The 
earlier  model  was  the  .MG  34.  A later  development  and  refinement  of 
this  m<»del  w'as  the  MG  42. 

An  amazing  light  full  automatic  and  semi-automatic  rifle  using  the 
full  powered  7.9  German  service  amrminicion  is  rhe  Fallschirmjaeger 
Gewehr  or  FG  42/44,  intended,  as  the  name  indicates,  for  use  oy 
parachute  troops.  With  its  folding  bipod  it  weighs  only  1 1 pounds. 
This  gun  is  a clear  indication  of  the  future  trend  in  fight  machine 
guns,  and  will  well  repay  study  by  designen  of  automatic  weapons. 

The  Russians  used,  besides  their  old  Maxim  Model  of  1910,  a new 
heavy  air  cooled  belt  fed  machine  gun  called  the  Degtyarev, 
Model  1939.  W'ith  its  heavy  flanged  air  cooled  barrel,  this  gives  much 
the  appearance  of  a Hotchkiss.  Another  gun  of  the  same  general 
type  and  appearance  is  the  Gurj'onov,  Model  of  1943.  ‘ 

In  the  field  of  light  machine  guns,  the  Russians  had  a 20  pound 
gas  operated  air  cooled  gun,  fed  from  a fiat  pan  magazine  holding 
47  shots,  called  the  Degtyarev  iModcl  DT,  which  has  been  in  service 
since  1926. 

The  Japanese  used  weapons  of  die  Hotchkiss  type  as  their  prin- 
cipal heavy  machine  guns.  They  were  called  the  .Model  92  (1932) 
6.5  min  machine  gun,  and  the  Model  01  (>941)  7.7  mm  machine  gun. 
Following  the  usual  Hotchkiss  principles,  they  were  gas  operated,  air 
cooled  and  strip  fed.  They  used  the  same  30  shot  feed  strips  that 
we  used  in  our  old  Benet-Mcrde,  that  was  standard  in  our  Army 


German  Fallschirm  Jaeger  Ccwehr  42,  or  F.G.  42,  automatic  rifle.  Jnicndcd.  as  indicated  by  the  name,  for  use  by  parachute  troops. 
An  extremely  light  weight  gun  of  advanced  design,  weighing,  mnipfete  with  Hi|>od,  only  a little  over  It  pounds. 


Russian  Degtyarev  li^'ht  machine  gun,  Model  DT.  It  is  gas  operated,  air  cooled  and  weighs  about  20  pounds. 

In  this  Photo  rhe  Flash  Hider  is  reversed. 


japweM?  heavy  machine  gun,  Hoichkicc  npe.  Year  <H  Model 


Japanese  Narabu  machine  gun.  Model  11  (1922).  Except  for  rhe  hopper  feed,  ic  follows  the  Hotchkiss  principle  of  design. 


JapancMf  wpy  of  Browning  aircraft  machine  gun. 


Machine  Guns  and  Thkir  Developmem 


135 


from  1909  Co  1916.  When  [ saw  hundreds  of  these  familiar  looking 
feed  strips  strewn  along  the  beach  at  Saipan  in  1944,  it  reminded  me 
of  my  Mexican  Border  Days  of  1916  as  machine  gun  instructor. 

A lighter  cun  of  the  general  tv'pe  of  a Hotchkiss  was  the  Japanese 
Nambu  Mo<^l  11  (1922)  6.5  mm  Light  Machine  Gun.  It  looks  a lot 
like  the  old  Benet-iVIercie,  but  uses  a hopper  for  the  cartridges 
instead  of  feed  strips.  It  is  air  cooled,  gas  operated,  and  weighs  about 
22  pounds.  It  was  largely  superseded  by  the  later  light  machine  guns. 

The  model  96  (1939)  6.5  mm  light  machine  gun  is  a lot  like  the 
Bren  in  appearance,  but  different  in  mechanism.  It  is  gas  operated,  air 
cooled,  and  weighs  20  pounds.  It  is  a very  effective  weapon. 

The  Model  99  (1939)  7.7  mni  Light  Machine  Gun  is  a weapon 
similar  to  that  just  described,  except  that  it  is  made  for  the  newer 
7.7  rnm  (or  .303  inch)  cartridge.  It  also  is  a highly  effective  w^eapon. 
The  Japanese  also  made  and  used  excellent  copies  of  the  Browning  and 
Lewis  machine  guns. 


Johmon  Light  Machine  Gun 

A gun  that  showed  great  promise,  hxn  never  attained  any  wide  use 
in  the  War  is  the  recoil  operated  light  machine  gun  designed  by 
Captain  Melvin  M.  Johnson,  of  titc  United  States  Marine  Corps 
Reserve. 

This  gun,  which  has  some  tjuiie  novel  and  desirable  features,  had 
the  bad  luck  to  make  its  appearance  just  at  a time  which  made  it  most 
difficult  for  it  to  attain  the  recognition  that  it  otherw^ise  probably 
would  have  received.  It  was  adopted  by  the  Dutch  in  194J,  but 
before  it  had  gotten  well  into  production,  the  Dutch  Colonial  pos- 
sessions passed  to  the  Japanese,  and  this  market  for  the  new  gun 
passed  out  of  existence. 

It  is  a short-recoil  operated  air  cooled  light  madiine  gun  vveighing. 
without  magazine,  only  12.3  pounds.  The  barrel  can  be  removed  and 
replaced  in  8 seconds  while  the  gun  is  hot. 

It  is  fed  from  removable  box  maga7ines  weighing  14  ouncc.s  and 
holding  20  rounds.  The  feeding  lips  which  guide  the  cartridges  into 
the  chamber  arc  machined  out  of  the  solid  metal  of  the  receiver, 
instead  of  being  shaped  out  of  the  thin  metal  of  the  magazine,  which 
is  easily  deformed.  This  feature  removes  a common  cause  of  mal- 
functions. The  gun  can  have  additional  cartridges  clip  fed  into  the 
magazine  from  the  right  side  of  the  gun  while  the  magazine  is  in 
place.  Thus  a partly  empty  magazine  can  be  replenished,  or  a different 
type  of  cartridge,  tracer,  for  example,  can  be  brought  into  use  in  an 
instant. 

A clever  arrangement  of  the  breech  mechanism  mikes  the  gun  fire 
from  an  open  breech  when  executing  full  auto  marie  fire,  thus  remov- 
ing the  danger  of  having  a cartridge  “cook  off’*  if  fire  is  interrupted 
while  the  gun  is  hot;  but  when  the  gun  is  used  as  a semi-automatic, 


The  Johnson  Light  Madiiae  Modei  19^1. 


Haix:her’s  Notebook 


138 

the  breech  closes  and  locks  on  the  cartridge,  after  which  a pull  on 
the  trigger  iires  the  gun,  thus  making  easier  the  artainment  of  ac- 
curacy. 

The  gun  that  was  adopted  by  the  Dutch  was  called  the  Model  of 
1941,  and  guns  of  this  model  were  used  by  parachute  troops  and 
raiding  parties  in  our  own  Army  and  Marine  Corps,  uses  to  which  its 
unusually  light  weight  made  it  particularly  adaptable. 

About  the  dnie  World  War  II  ended,  an  improved  experimental 
model  called  Model  1944  embodied  some  new  features  shown 
to  be  desirable  fay  combat  experience.  I'his  was  further  developed 
into  the  Model  1945,  which  with  attached  inonopod  rest  weighs  only 
15.5  pounds.  This  gun  has  a gas  assist  tn  boose  the  recoil  of  the  barrel 
ami  increase  the  cyclic  rare,  barrels  on  this  model  can  be  changed  in 
six  seconds,  and  this  should  be  done  every  looo  to  1200  rounds  when 
firing  ac  the  race  of  50  bhots  per  minute. 

Commencing  with  the  gun  empty,  one  man  can  load  and  fire  iHo 
shots  in  I minute  full  aucomaric,  and  60  aimed  shots  in  1 minute 
semi-autumatic. 

A two  man  team  of  loader  and  gunner  can  load  and  fire  100  shots 
in  18  seconds  or  200  in  37  seconds,  thus  maintaining  a rate  of  over 
300  shots  per  minute.  A three  man  crew,  with  spare  magazine  and 
spare  barrel  can  deliver  1000  shots  in  .six  ni inures,  though  they  will 
have  changed  barrels  9 times  during  that  period.  Of  course,  unless  it 
is  necessary  to  fire  at  the  maximujn  rare,  the  number  of  barrel 
changes  would  he  much  less. 

It  will  he  seen  that  this  gun  has  some  very  advanced  features,  and 
it  is  a highly  effective  weapon  of  its  type. 


VI 

The  Military  Semiautomatic  Rifle 

WHAT  is  the  reason  for  a semiautomatic  rifie,  was  not  the  Spring- 
field  good  enough?  A very  little  rcHcccion  will  answer  this 
question.  Consider  a soldier  engaged  in  a skirmish.  He  is  lying 
prone  on  rhe  ground  wirh  his  ride^  trvitig  to  make  himself  as  in- 
conspicuous as  possible.  Somewhere  in  the  distance  one  of  the 
enemy  soldiers  shoots  ac  him.  The  chances  are  he  does  not  know 
where  the  bullets  are  coming  from.  In  World  War  1 one  of  the 
things  that  surprised  our  soldiers  at  first  was  the  fact  that  many 
of  them  went  through  several  entire  battles  without  seeing  any  of 
the  enemy  soldiers.  Suppo.se  our  soldier  docs  locate  an  enemy’s  helmet, 
barely  distinguishable  against  the  landscape  zoo  or  300  yards  away. 
He  has  detected  some  n^ovcmcnc  and  he  knows  that  this  is  all  he 
can  sec  of  one  of  the  enemy  soldiers,  so  he  decides  to  use  it  as  a 
target.  He  cakes  careful  aim  and  fires,  and  a puff  of  dust  a little  in 
front  of  and  a lirrlc  to  the  right  of  the  point  of  aim  shows  where 
his  bullet  struck.  Then,  in  his  excitement,  he  yanks  back  the  bolt, 
.shoves  it  forward  again,  turns  it  down  and  locks  it,  and  what  hap- 
pens? The  chances  are  that  the  resulting  movement  of  his  rifle  has 
disturbed  his  line  of  sight  for  the  moment,  and  when  he  looks  back  he 
can  no  longer  locate  the  object.  Then,  again,  he  has  made  quite  a 
movement  himself  and  the  alert  eyes  of  the  enemy  may  have  detected 
this,  and  he  may,  in  turn,  be  serving  as  a target. 

Consider,  however,  that  this  soldier  has  a seniiautomaiic  rifle.  He 
rakes  careful  aim,  presses  the  trigger,  and  observes  a puff  of  dust 
a little  in  from  of  and  a little  to  the  right  of  where  he  wa.s  aiming. 
Ini  mediately,  without  taking  his  eyes  from  die  sights,  he  shifts  his 
point  of  aim  a little  to  the  left  and  a little  higher,  presses  his  finger 
CO  the  trigger,  and  this  time  his  bullet  will  probably  find  its  mark. 

.Many  years  ago,  the  Army  recognized  the  desirability  of  having 
the  service  rifle  operate  on  the  self-loading  principle,  and  .sent  out 
frequent  invkatioas  to  inventors  to  submit  models  for  test;  bur  during 
a period  of  some  thirty  years,  little  success  artcuded  these  efforts. 

For  a while,  the  recoil  operation  seemed  to  he  a favorite  with 
inventors,  but  they  ran  into  several  dlfliculcies,  sucli  as  trouble  in 
attaching  a bavoncr.  At  this  writing,  rhe  bayonet  may  be  considered 
as  obsolete,  but  chat  was  not  so  a few  years  back,  The  fact  that  the 
barrel  esmnoe  be  fixed  rigidly  to  the  receiver  or  stock,  but  must  be 
free  to  slide  back,  posed  a problem.  Some  inventors  met  it  by  encasing 
the  barrel  in  a tube,  but  while  this  is  all  right  for  a hunting  rifle, 


*39 


The  Remington  autoloading  ride^  model  S (now  model  81)  fitted 
trying  to  find  a suitable  semiautomatic  rifle  fur  adoption,  a number 
issued  to  the  Army  for  tactical  tests  to  determine  the  best  way  to  use 


for  militar>*  use.  During  the  years  around  1930«  when  we  were 
of  ihe^  Remingtons,  io  .35  caliber  were  fitted  up  tike  this  and 
a semiautomatic  rifie  in  various  situations. 


Th£  iVliLiTARY  Semiautomatic  Rikle 


141 


which  is  fired  only  occa^onally,  it  will  not  do  for  a military  gun, 
which  muse  stand  continued  firing;  the  heating  of  the  barrel  is  coo 
severe. 

Finally  a recoil  operated  gun  was  designed  by  Capr.  Melvin  M. 
Johnson,  U.  S.  Marine  Corps  Reserve,  which  overcame  the  previous 
objecdons  to  this  method  of  operation.  This  came  after  the  Garand 
had  already  been  adopted  by  the  Army,  but  the  Netherland  Indies 
guver  nil  lent  ordered  a larage  nuniber  of  these  guns,  and  some  of 
them  saw  service  with  onr  forces  in  the  Southwest  Pacific.  In  actual 
scrv'ice  they  were  not  liked  as  well  by  their  users,  the  U.  S.  Alarine 
Corps,  as  were  the  Garands.  The  Johnson  gun  w'as  nevertheless,  a 
fine  serviceable  weapon,  probably  second  only  to  the  Garand  among 
the  semiautomatics  of  World  War  II. 

Early  Ordmfice  Designs 

In  1916  our  Ordnance  Department  attempted  to  design  a semi- 
auromacic  rific  at  Springfield  Armory,  and  another  at  Rock  Island 
Arsenal.  Both  of  these  guns  were  gas  operated,  and  the  already 
difficult  problem  of  gas  operation  was  complicated  by  the  require- 
ment laia  down  by  our  i^fty  govcmiiictu  rhar  the  guns  must  be 
made  so  that  if  possible  the  regular  hand  operated  Springfidds  could 
be  converted. 

Both  of  these  guns  were  extremely  crude,  chough  the  Rock  Island 
model  was  better  than  that  produced  by  Springfield.  This  Rock 
Island  gun  had  a sort  of  sliding  cage  over  the  breech,  with  a cam  in 
it  CO  operate  the  bolt  handle,  and  when  I showed  this  to  Mr.  Browning 
in  1917,  he  remarked  with  a dry  smile,  "‘Where  do  you  put  on  the 
cheese?’*  We  saw  the  point  at  once,  for  the  resemblance  to  a rat-trap 
was  rather  marked. 

Many  of  the  models  submitted  by  inventors  were  of  the  gas 
operated  type,  aixl  the  presence  of  a gas  cylinder  under  the  barrel,  or 
at  the  side  of  it,  or  on  top  of  it,  inevitably  added  quite  a bit  of 
w'^ht  and  bulk. 

Tlien  another  trouble  with  these  guns  was  that  gas  was  capped 
off  the  barrel  at  such  tremendous  pressure  that  it  w»as  hard  to  handle 
it  without  introducing  .severe  strains  on  the  gun.  When  the  bullet 
passes  the  gas  port  in  the  barrel,  the  pressure  at  that  point  will  be 
anywhere  rrum  40,000  down  to  5,000  or  10,000  pounds  per  square 
inch,  depending  upon  where  the  port  is  located.  The  closer  to  the 
breech  it  is,  naturally,  the  higher  will  be  the  pressure.  Assuming  that 
the  port  is  at  the  point  where  the  pressure  is  25,000  pounds  to  the 
square  inch,  a sudden  application  of  this  enormous  pressure  on  the 
head  of  the  piston  slams  the  breech-block  open  with  extreme  violence, 
and  the  result  is  not  only  undesirablv  quick  opening,  tearing  the 
heads  off  the  empty  cartridge  cases,  and  such  troubles  as  these,  but 
also  excessive  breakage  of  parts. 


n 

4 

1 

V* 

The  Johoson  SeaiMuiomatic  Ride  Minle^  1941. 


144  Hatcher’s  Notebook 

The  logical  thing  to  do  was  to  move  the  gas  port  as  far  forward 
as  possible,  where  die  pressure  would  nor  be  so  great,  and  reduce 
the  area  of  the  port  so  chat  the  gas  w'as  throttled  down  to  a lower 
pressure  before  striking  the  piston.  By  doing  these  things  a number 
of  very  successful  gas-opera  red  guns  have  been  made;  but  there  is 
auoclicr  disadvantage  to  the  gas-operated  system,  and  chat  is  the  hole 
bored  in  the  barrel  to  form  the  gas  port.  It  is  dilTiculr  to  dean  this 


Top:  Rychiji^c  retoi]  opcr^icJ  rifle.  Thi$  rifle,  niitde  in  Switzerland,  was 
based  oq  the  straight  pull  Sibmidc  Rubin  action,  and  was  chambered  lor  the 
Swiss  service  ammunitton. 

Middle:  Rychiger  type  rifle,  made  lor  the  U.  S.  Service  ammunition  bv  Major 
hlder  of  the  Ordnance  Oeparimeoi  during  1918. 

Bottom:  Bommarito  recoil  operated  rifle  MibmiUcd  for  test  during  1918.  It 
baa  a toggle  joimed  bceech  lock,  like  that  on  the  Uiger  pistol. 


hole,  SO  that  it  is  always  a point  where  rust  and  corruskin  arc  likely 
ro  start. 

Gas  operation  was  successfully  applied  to  machine  guns  long  before 
it  was  CO  shoulder  rifles.  In  machine  guns,  the  moving  parts  can  be 
made  heavy  enough  to  absorb  the  sudden  and  powerful  impact  of 
the  gas.  Moreover,  the  pressure  of  the  gas  on  the  piston  endures 
for  only  a very  small  time  interval  and  if  the  piston  can  be  made 
rather  heavy,  it  will  have  a better  chance  to  absorb  enough  energy 
during  this  very  brief  interval  to  carry  it  through  its  stroke. 

With  the  shoulder  rifle;  conditions  arc  verj^  nnich  more  difliculr. 


Aa  tarJ>  example  of  (he  semiautomatic  rifle  submitted  for  test  bv  (he  United  States  Machine  Oun  Compaut.  Based  on  a Berthier  design 


< 

s 

✓ 

S 

i ) 

X 

Th«  Bnng  semiautomatic  riBe,  model  of  1911<  This  gun  is  operated  by  the  pull  of  tlte  mux^le  bUn  on  a cap  over  the 

mur?Je.  The  j>ul(  is  ironsmiucd  to  a lever  k the  breech  through  a thm  rod.  This  gun  passed  a most  creditable  test,  but  failed  uf 
adoption  prlnclpall)'  because  die  very  chin  barrel  heaied  up  too  mneh  in  rapid  hre.  The  gun  is  shown  with  a muzzle  protector  in  place 
over  die  end  oi  the  barrel,  it  muse  be  removed  before  firing. 


The  improved  .256  Bang  rifle  submitted  b\  Mr.  Bang  to  the  Ordnance  Oepartmeot  in  1927.  It  did  nut  differ  greatly  from  the 
original  Bang.  The  action  is  shown  dosed. 


l[[p  Mii.iiary  semiautomatic  Rulf, 


*47 


The  piston  and  ocher  moving  parts  cannoc  be  made  heavy  or  the 
gun  will  weigh  too  much;  and  light  parts  do  not  have  enough  inertia 
CO  carry  through  the  rearward  motion  after  the  gas  pressure  is  gone 
unless  the  impact  of  the  gas  is  made  extremely  violent.  The  result 
has  been  chat  in  most  gas-opcrared  shoulder  rifles  the  light  piston 
gets  up  energy  enough  to  open  the  breech  against  the  spring  action 
by  being  slammed  to  the  rear  with  very  high  speed,  and  this  violent 
action  is  conducive  to  very  high  breakages. 

The  Batig  Rj/lc 

In  jyri,  Sorcii  Hansen  Bang,  of  the  Danish  Recoil  Rifle  Syndicate, 
Copenhagen,  suhTTiicccd  a rifle  which  passed  a remarkably  satisfactory 
resc.  Its  performance  was  better  than  that  of  any  other  semi-auromatic 
rifle  submitted  up  to  that  thiic  or  for  many  years  u>  come.  It  is 
described  on  page  62. 

The  Bang  gun  was  big  and  bulky,  but  very  light.  The  lightness 
was  obtained  by  hollowing  out  the  stock  so  char  in  some  spots  it  was 
little  more  than  a shell,  and  by  turning  down  the  barrel  so  that  it  was 
reduced  to  the  minim  uni  in  diameter. 

While  this  gun  passed  a splendid  test  as  far  as  the  functioning  was 
concerned,  the  barrel  was  far  roo  lighr  ro  stand  the  heat. 

The  muzzle  cap  used  by  Bang  was  nuicli  like  one  patented  by 
Sir  Hiniin  Maxim  in  1885.  Such  a principle  was  experiiiicnted  witn 
by  John  Browning  in  1889  on  a model  gun  built  by  him.  It  was 
used,  but  not  patented  by  Bang,  probably  on  account  of  Maxim’s 
patent.  It  was  used  in  an  auto-loading  rifle  built  by  Mr.  Garrison 
of  the  Remington  Arms  Co.,  about  the  time  of  World  War  I,  using 
the  breech  action  of  the  Remington  auto  loading  rifle.  Grant  Ham- 
mond also  patented  some  niodilications  of  chis  principle.  The  rifle 
submitted  for  test  at  Springfield  in  1921  by  General  Liu  of  China 
had  the  Bang  muzzle  attachment  in  almost  the  identical  form  in 
which  Bang  used  it.  The  Puteaux  Machine  gun,  used  by  ihe  French 
for  stmic  years  used  a similar  type  of  gas  take-off.  The  Rhein  me  lali 
Semi-automatic  rifle,  designed  bv  Kan  Heincuiann,  and  tested  at 
Aberdeen  Pr<Jving  Ground  in  J929  in  the  Pedersen  .276  caliber  had 
a muzzle  cap  almost  exactly  like  the  one  used  bv  S.  II.  Bang. 

Hjtcher  Self  Loading  Rifle 

in  1920,  Alajor  James  L.  Hatcher,  (now  Colonel;  brother  of  the 
writer)  built  a semiaiiromaric  rifle  ar  Spriugfleld  Armory,  which  had 
the  same  general  cvpc  of  muzzle  cap  gas  take-off  that  Bang  used, 
but  which  was  a big  improvement  on  die  Bang  as  far  as  ruggedness 
was  concerned,  and  elifninated  the  defects  formerlv  noted  in  the 
original  Bang.  He  completed  his  first  model  rifle  in  the  phenomenally 
short  time  of  four  months,  and  while  this  rifle  passed  an  excellent 
preliminary  test,  breakages  eventually’'  developed,  indicating  the  need 


•T^ 


♦> 


Two  models  of  the  Liu  semi  automatic  rilt«  ie$i^  at  Sptin^lielJ  io  1918. 
follow*  the  Bang  principles  very  closely. 


Thi*.  Chinese  designed  Hfle  suhtnitted  by  General  I.iu 


The  Hciocmarn  rifle,  another  modihcacion  of  the  famoas  and  popular  Bang^  desigoed  by  Karl  Heinemann  and  submitted  b> 
Rhcmische  Mcttaliwaren  und  Maschinen  Fabrik.  The  muzzle  attadimeoi  aod  ga^  operation  are  the  same  as  in  the  Bang,  buc  ihc  breech 
closure  is  a toggle  jninted  breech  block  opening  horizooially  ofl  the  right  side  of  the  receiver.  This  gun  embodies  a neat  device  for 
overcoming  the  tendency  oi  the  breech  block  to  bounce  open  slightly  after  siaminiag  shut,  i’he  hnger  lever  lor  opening  ibe  action 
by  hand  is  pivoted  loosely  on  the  side  of  the  breech  block.  Wlien  the  breech  block  slams  shut,  the  £nger  lever,  which  has  been 
following  along  behind,  catches  up,  and  just  as  the  block  starts  to  bounce  open,  strikes  a blox»  which  kills  the  lx»unce  compIeteJj, 


Clnse  up  view  of  ihe  Rheinmetall  $emi automatic  riflr  designed  by  Karl  Heiocmann.  Toggle-action  bfeech  is  in  the  open  position 
Note  the  loosely  pivoted  piece  ot  metal  attached  lo  the  finger  hook  to  kill  ihc  rebound  when  the  breech  block  slams  shut. 


Hemeiiiaan  semiautomatic  rifle,  made  for  die  *^.9211110  German  service  cartridge,  captured  in  Germany  during  World  War  II.  This 
very  similar  to  the  .2~^6  model  of  this  gun  that  was  tested  in  Aberdeen  Proving  Ground  in  1929. 


SemiautoiMatu  tlAtt  huih  ac  Sprinfttield  Armon  in  192U  by  Major  Jame^  1..  Haichcr.  It  cmpiovecj  a sliding  nuu^U  cap  ac- 
tuatop.  similar  to  chat  used  hy  Baap.  Thnuph  U was  pr<HJuted  in  the  remarkably  shore  time  of  /our  motuhs,  ii  w'us  extremely 
simple,  performed  well,  and  gave  great  promis*  of  success.  Unforninaielv,  as  the  rille  was  undergoing  some  tbanggs  found  desicaMc 
in  H preliminary  test,  the  designer  was  ordered  to  other  duts,  and  never  had  an  opportunity  to  perfect  the  design. 


Second  semiaucomacic  rifle  designed  by  Major  (oow  Colcmcl)  James  L.  Hatcher,  coastructed  by  him  while  stationed  ac  Aberdeen 
Proving  Ground  in  1923,  ii  used  a muzzle  sleeve  actuator,  of  the  Bang  type  as  did  his  earlier  model. 


The  Military  &miautomatic  Rifle 


*55 

for  redesign  of  some  of  the  parts,  as  usually  happens  with  an  in- 
ventor’s first  model.  The  board  which  reseed  the  gun  suggested  certain 
changes,  but  before  they  could  be  gotten  underway,  the  designer 
was  ordered  to  another  station,  thus  effectively  putting  an  end  to 
this  effort. 

This  gun  business  in  those  days  was  something  like  a horse  race. 
There  were  a couple  of  favorites  which  seemed  to  be  coming  into 
the  home  stretch,  and  they  had  very  heavy  backing  in  some  quarters, 
and  certain  information  which  came  to  me  in  a highly  confidential 
way  at  that  time  led  me  ro  conclude  that  the  change  of  station  which 
interrupted  this  work  was  not  acxidental. 

Major  Hatcher  was  given  permission  to  work  on  an  improved 
model  at  his  new  station  “in  addition  to  his  other  duties.’*  He  did 
succeed  under  very  great  handicaps,  in  turning  out  a second  model, 
but  as  far  as  I know,  never  did  actually  have  it  tested  by  the  official 
board. 

Thmnpson  Antovlflt 

Another  scheme  for  a semiatitomadc  riffe  was  based  on  the  so- 
called  Blish  principle,  already  mentioned  on  page  44. 

It  was  on  this  principle  that  the  Thompson  .semiautomatic  rifle  was 
huilc  by  General  J.  T.  Thompson,  retired,  formerly  Chief  of  the 
Small  Arms  Division  of  the  Ordnance  Department. 

The  Thompson  autorifle  that  I tested  at  Springfleld  Armory  In 
1921  worked  as  long  as  the  oiled  pads  were  used,  but  it  opened  with 
extreme  speed  nnd  ejected  the  cartridges  with  such  force  that  the 
empty  shells  in  one  test  were  actually  stuck  into  a heavy  wooden 
door  about  twenty  feet  to  the  right  of  the  ejection  port. 

Anyone  standing  to  the  right  of  this  gun  could  have  been  very 
severely  injured  by  these  flying  missiles.  Morcovei*  the  bolt  handfe 
came  back  witli  such  speed  that  it  would  simply  have  sheared  off 
the  thumb  if  the  operator  had  been  so  unwary  as  to  put  his  thumb 
up  alongside  the  receiver.  Obviously  the  Thompson  guns,  of  which 
a number  of  models  were  tested,  neA^ec  had  a chance  of  adoption. 

World  War  I Designs 

During  World  War  I.  the  French  quietly  placed  on  the  firing 
line  a long,  heavy  ga.s-operatcd  rifle,  using  the  8 mm  Lebel  cartridge, 
which  tiren  was  the  standard  Frcijch  ^rvicc  cartridge.  Tliis  rifle, 
called  the  St.  Etienne,  was  rather  simple  but  effective.  It  used  the 
cartridges  in  clips  of  five,  which  w'cre  placed,  clip  and  all,  in  a hinged 
magazine  under  the  receiver.  The  bolt  was  a straight-pull  affair,  and 
the  thrust  of  the  gas  piston  simply  shoved  the  bole  handle  to  the 
rear,  causing  it  first  to  rotate  the  bolt  to  the  unlocked  position  by- 
means  of  a cam,  then  to  pull  it  open.  The  rifle  had  a rather  violent 
opening  action,  owing  to  the  uncontrolled  thrust  of  the  gas.  The 
gun  was  used  in  the  war,  but  not  much  was  heard  of  it. 


The  Thompson  Auiori£e,  Colt  model  k92\. 


55 


A7/Z£ 


n; 


Sr.  Frienne  semiautomaiic  rifle.  Thi^  simple  pas  operaied  arm  was  used  b>'  ihc  French  ia  World  War  I,  and  was  copied  in  our 
.^0  caliber  by  Major  hlder  in  1918. 


Int  MlLltARV  S^NtJALrOMAMC  [<IM» 


*57 


Tup:  Mon^iragon  scmiaaiomaiic  fU^^,  a «i|H:raicii  design  pu fenced  h\ 

Manuel  MnnJragon  of  Mexico.  AugUM  \*)04.  and  adopced  by  Mexico  in  1911. 
[(  was  made  in  Switzerland  b>  the  Scbweizerixche  InduMriel  CTCH'ltschafi  At  Ncu* 
hau5cn.  on  the  Swiss*Oerman  border.  >X’iih  the  advriu  of  World  War  I the 
produaien  was  divcricd  to  Ciermany,  and  the  use  of  the  pm  Ky  Mexico  was 
diccominuccl. 

Middle:  *I1fv  Siergian  rl6c.  This  seas  not  semiautomatic,  hut  was  m.imially 
operated  in  the  same  manner  as  a pump  auiun  shotgun,  hy  means  of  the  hand 
grip  under  the  forearm.  *lhix  was  jointed  so  it  could  he  folded  into  a slot  in 
ihc  siiKk  when  not  in  use. 

Bo  I Com:  l*hc  Murphv'Manning  gas  operated  semiuutomaiu,  designed  and  hut  It 
Sy  two  Springheld  Armctry  employ alHuu  I915. 


During  the  war  of  iqi4-i9i8,  the  Germans  used  t|tiitc  .1  few  i^as 
•ipcr.ucd  rifles  of  the  kind  called  the  .Mtmdr^igon.  which  had  hcen 
adopted  bv  the  .Mexican  Government  in  u)n.  This  rifle  was  dc- 
v'cloped  hv  the  Mexican  General  .Mondragon  at  the  plant  of  rhe 
Sweizctische  Industrie!  (le^cllschaft,  at  Ncuhausen  in  Switzerland. 
This  is  only  a few  mile??  from  (leniianv;  in  fact  it  is  so  close  that 
when  I went  there  to  investigate  this  rifle  the  train  from  the  next 
Swiss  town  wandered  back  and  forth  acrojw  rhe  border.  The  train 
went  straight  while  the  border  wound  in  and  our.  .\s  stated  above, 
this  gun  had  been  adopted  bv  the  .Mexicans  just  before  M'oild  War 
I.  When  the  war  broke  out,  it  was  no  longer  possible  t<»  send  the 
guns  to  .Mexico,  and  the  entire  production  was  diverted  to  Gennanv. 
rhe  iMondragon  compares  rather  favoral>lv  with  some  of  the  gas 


15^  MaICIU.RS  NlllHMHlk 

ypcnucj  semi  nutoinatics  used  in  W’orkI  Wav  II,  such  iis  the  'I'olsiiiev 
and  the  Gesv.  43. 

During  tlic  carlv  months  of  our  war  with  (xermanv  in  [917  and 
jK,  the  Ordnance  Dcparrnicnt  commisssioned  as  Major  an  arms  de- 
signer of  the  Stevens  Arms  Co.,  named  Klder,  and  gave  him  the 
task  of  attempting  ro  gee  out  a semiaut<Mmric  riHc  tlwr  we  cotdd 
use  in  the  war.  Ahijor  Hder  copied  the  Sr.  luicnnc  in  .^o  caliher 
ami  did  the  same  vN'irh  a very  pmiiisincr  Swiss  >htuT  recoil  rifle 


Clo5C  up  viiw  of  joirued  )<Hk  ihv  Ooitimariio  recoil  action.  A 

downward  proj«cong  arm  on  rearward  mcml>cr  of  the  breech  Ho<k  me>hes 
in  a dcprcH>ion  in  die  frame,  ami  h gtar«d  up  that  as  the  barrel  moves  to  rhe 
rear,  the  breech  auion  is  forcibly  moved  to  the  open  po>ition  shocsn. 


called  the  Rvcliigcr.  Major  F.ldcr,  wlur  worked  under  mv  super- 
vision when  I was  (!hicf  of  the  Machine  (inn  and  Small  Arms 
Sccticm,  l^nginccnng  Division,  Ordnance,  in  1918,  produced  some 
very  crcdital)lc  models,  hut  tlie  war  ended  before  any  of  them  had 
been  actually  put  into  production  for  war  use. 

The  Federsen  .2~6 

A rifle  which  is  neither  c^s  operated  nor  recoil  operated  was 
huilc  by  Mr.  J.  D.  Pedersen.  Mr.  Pedersen  is  a gun  designer  of  im 
mensc  experience.  Years  ago  he  designed  the  Remington  pump  shot- 
gun, wliicli  accained  grear  conmiercial  .success,  and  afterwards  he 
designed  mimerous  rifles  for  the  Remington  Arms  Company,  in- 
cluding the  slide-action  .a.  He  also  designed  the  Remington  auto- 


Top:  V.  S.  Rifle,  Cal.  .30,  model  of  1903,  for  comparison  with  the  semiautomackv  diowu  bdu>v. 

Middle:  Garand’s  chird  model,  a gas  opetaicd  gun  built  to  shoot  (he  Pedersen  i"<5  cartridge.  This  gun»  IfUer  changed  to  30 
calil>er,  became  the  present  Ml. 

Bottom:  The  Pedersen  .276.  A retarded  bio  whack  gun,  which  eliaiinaied  all  die  complications  of  gas  operation  oc  recoiling  barrel 
by  an  exceedingly  cleTcr  method  of  opposing  the  opening  teiuJencv  of  the  breech  by  the  inertia  of  the  parts  acting  di rough  a favor- 
able leverage.  It  passed  a highlv  satisfactory  test,  bui  used  waxed  cariridges,  a fact  which  weighed  aga;n$t  lU  more  on  theoretical 
chan  on  practical  grounds. 


1 1 A1  CUKK'.S  N O TF  B4HHC 


(6o 

luacic  pisct>l,  and  tiic  Peder>cii  device  whicli  was  one  of  our  most 
closely  guarded  secrets  of  World  War  I, 

Along  about  1922  j\1r.  Pedersen  approached  the  Ordnance  Depart- 
ment with  a plan  for  a scmiauconiatic  rifle  on  an  entirely  new  design. 
I'he  design  was  so  promising  and  Mr.  Pedersen’s  reputation  as  a 
designer  so  great,  that  the  Ordnance  l>ep.iitnent  decided  to  build 
the  rifle.  As  a result  Mr.  Pedersen  was  ciiiployed  and  his  rifle  w'as 
bn  lie  at  Springfield  Armory.  Tlic  fin>i  test  was  successful,  and  twenty 
samples  were  built,  which  went  out  to  rhe  infantry  and  cavalry  for 
.service  test.  Some  of  these  twenty  rifles  were  also  denionscraced  from 
rime  to  time  at  Guiip  Perry. 

Mr.  Pedersen’s  rifle,  like  General  Tlionipsons  Is  what  niav  be 
called  a delayed  hlow^-back,  hut  in  thi.s  gun  there  arc  no  screw  threads 
on  the  breechblock.  'The  breechblock  is  .1  toggle  joint,  or  crank, 
very  much  in  principle  like  what  was  dc.se rihed  in  connection  with 
the  Maxim  machine  gun,  but  with  this  difference,  that  this  crank 
is  never  on  dead  center.  It  is  always  just  a little  bit  out  nf  line,  so 
that  the  moincne  pressure  conics  on  clie  cartridge  the  toggle  joint 
begins  to  open.  If  it  were  merely  a hinged  crank  with  a pin  joint 
where  the  connecting  rod  joins  to  it,  ic  would  open  too  fast.  The 
crank  and  connecting  rod  are,  however,  not  hinged  together  wirh  a 
simple  hinged  joint,  but  each  has  a cam  surface,  and  as  the  breech- 
block moves  back  and  the  toggle  joint  breaks,  these  two  cam  surfaces 
roll  together  in  such  a w'ay  as  to  delay  the  speed  with  which  the 
line  of  thrust  gets  away  from  a straight  line.  Thib  again  this  blow- 
back  mechanism,  while  it  docs  not  have  much  w'cighr.  is  as  hard  to 
move  and  as  slow  to  move  as  if  it  did  have  the  weight  ihcrc.  It  is 
hard  to  move  because,  when  the  thrust  comes  on  the  head  of  the 
breech-block,  it  is  transmitted  almost  in  a straight  line  to  the  big 
pivot  pin  in  the  back  of  the  frame.  When  this  thrust  is  exerted,  the 
center  of  the  toggle  joint  moves  upward,  but  this  center  must  move 
up  a considerable  distance  before  the  head  of  the  bolt  moves  back 
appreciably.  A lot  of  upward  speed  must  be  put  into  the  center  )f 
the  toggle  joint  before  the  head  of  the  bolt  goes  back  verv  far,  and 
this  delav.s  the  opening  of  the  gun  sufficiently  to  enable  the  powder 
pressure  to  fall  before  the  cartridge  case  can  get  out. 

Mr.  Pedersen  finally  completed  twenty  of  his  rifles  at  Springfield 
Armorv  in  1927,  ana  these  were  sent  out  for  service  test.  In  the 
iiicaritlme  Frankford  Arsenal  had  been  experimenting  with  .276 
cartridges,  and  several  hundred  thousand  of  these  cartridges  were 
made  up  for  use  in  testing  the  twenty  Pedersen  rifles. 

In  1927  the  Pcderseti  rifles  w^erc  tested  by  the  Infantry  and  Cavalry 
and  were  found  to  be  suitable  for  military  use.  It  was  decided,  how- 
ever, chat  before  adopting  this  rifle,  we  would  make  a thorough 
test  of  all  the  ocher  modek  w'hich  were  available,  and  accordingly 
notice  was  sene  out  to  inventors  that  the  War  Department  would 


The  Pedersen  .2“Ck  shown  whh  action 


Pedcr>vn  .270  scmiauconiacic.  ^ktov^jn^  iui<»ii  ux  iloxtJ  |>u>iiioii. 


Japanese  copy  of  the  Pedersen  semiauiomaiic  rifle.  Unlike  ibe  Pcdcr«icn,  ibis  rifle  uses  a rotary  majjazine  similw  to  the  Schoenauer 
type,  or  to  (hat  used  io  (he  Savage  Model  1899,  and  is  arranged  co  be  loaded  by  siripping  cartridges  from  a clip  like  that  of  (he 
Springfield  or  Mauser. 


I'liR  \1tirr\R^  S^^tIAt  To\r.\TK:  Riiir 


Cloxc  up  of  ciie  iu«^huniini  (hr  Japanese  copv  xA  tlir  Pcdccscn  stmiaucomacic 
ritlc,  roun  <»r  ivjk*  maga/lnc.  Only  iwo  samples  of  ihis  rifle 

were  found,  ll^cs  were  in  an  arsenal  about  7 miles  from  Tokyo»  aod  were 
marked  No.  1 and  No.  Z,  respcciivel),  so  i(  is  likely  ihai  ihcy  were  cxpcrimcmal 
models,  and  (hai  (hey  were  (ho  only  ones  made. 


ludd  II  test  of  scniiauioniailc  rifle?,  in  July  1929.  These  rifles  were 
to  fire  the  new  .276  amiminirion  which  l>v  that  rime  had  been  approved 
for  adopcioii  as  the  service  cartridge  tor  any  new  semiaacomacic  that 
met  the  final  tests. 

The  improved  (ijra/ui 

la  1928.  Mr.  Garand  had  started  to  work  on  an  improved  model, 
in  which  he  had  abandoned  his  primer  operation  in  favor  of  gas 
operarion.  His  new  rifle  was,  of  course,  of  the  .276  caliber. 

Mr,  Ciiirand’s  new  gun,  contrary  to  the  usual  practice  in  gas 
operation,  did  nut  have  a gas  pore  in  the  barrel.  Instead,  he  used  a cap 
over  the  muzzle,  similar  co  the  cap  used  by  Bang,  with  this  important 
difference;  the  Garand  cap  did  not  move.  See  page  58. 

'There  is  an  entry  in  my  notebook,  made  some  years  ago  as 
follows:  ‘"Garand’s  muzzle  cap  patented  by  L.  Silverman  of  Cray- 
ford,  Kent,  assigned  to  Vickers  Sons  and  Maxim,  U.  S.  Patent  618,743, 
Jan.  31,  1899J' 


Csech  scniiautoinanc  rirte  i«si«d  ai  Aberdeen  Pro'injs  Ground  in  1929 • Ic  was  d«si(^ned  by  HoUk.  and  submittsd  hy  th«  “ZB" 
ftrm,  (Cesko»lov«nska  Zbrojovka,  of  Brno,)  h was  chambered  for  ihe  .2“0  cartndye. 


The  White  semiautomatic  .27(5.  This  was  one  of  ihe  rifles  tested  at  Aberdeen  in  1929.  It  had  an  ominialK  short  tompaa  action, 
and  a system  of  admitting  a small  portion  of  gas  into  a hollow  pis  .on  and  then  cutting  off  the  supply,  after  the  manner  of  a slide 
>aUe  in  a steam  engine,  so  the  gas  suuld  au  by  expunsion  and  tlus  soften  the  blow  of  the  piston. 


The  Military  SRMi.AirroMATir  llrf-rr  165 

G a rand  used  this  arnmgejnenc  on  his  early  production  of  M i 
rides,  hut  soon  changed  to  the  conventional  gas  port  near  the  muzzle. 

The  Garand  gas  operated  gnn  was  characterized  by  extreme 
simplicity  and  clean  design  nf  all  the  pairs.  It  had  tmly  about  60 
pieces,  which  is  cunsidcrablv  Il’ss  than  the  number  in  the  Springfield 
’03.  The  first  of  these  guns  weighed  about  the  same  as  the  1903 
Springfield.  The  gun  had  a ten  round  magazine,  with  an  “en  bloc'’ 
clip;  a receiver  peep  sight,  with  clicks  for  botlt  elevation  and  windage; 
a pistol  grip  stock,  with  more  length  chat  that  of  the  Springfield 
’03,  and  with  a higher  comb  for  more  comfort  in  prone  shooting. 

The  official  test,  held  at  Aberdeen  Proving  Ground  in  1929,  in^ 
eluded  the  Pedersen  and  G a rand  rifles,  the  Thompson  rifle,  a Brown- 
ing of  the  short" recoil  tvpc  made  by  tfic  Cole’s  Patent  Fire  Arms 
Manufacturing  Co.,  and  three  Fnropean  rifles— the  Brauning,  invent cd 
by  a Belgian  (which  should  not  be  c<m£used  with  the  American- 
invented  Browning  guns  made  in  Belgium),  a Czechoslovakian  gas- 
operated  rifle,  and  a rifle  invented  by  Karl  Heinemann,  who  designed 
the  German  Parabelkim  aircraft  machine  guns  during  the  first  world 
war. 

As  a result  of  this  Aberdeen  test  of  1919,-which  I attended,  as 
it  came  under  my  direct  .supervision  as  Cliicf  of  tite  Small  Arms 
Division,  Technical  Stalf,-thc  Garaiid  .y^6  came  our  on  top,  and  it 
was  decided  to  make  twenty  of  them  for  an  extended  service  test, 
as  had  already  been  done  with  die  Pedersen.  The  test  was  completed 
in  1932,  aiuf  it  then  remained  to  determine  which  of  rbc.se  two 
highly  satisfactory  rifles  would  be  adopted  for  service  use  by  the 
army. 

In  the  meantime  the  British  apparently  had  shown  a disposition 
CO  adopt  the  same  rifle  wc  finally  chose,  so  Pedersen  went  to  England 
and  worked  with  Vickers,  Ltd.,  tooling  up  for  his  rifle,  which  most 
people  apparently  thought  it  certain  wc  would  adopt. 

Apparently  tlie  Japane.se  thought  so  too,  for  recently  I have  seen 
a rifle  of  the  Pedersen  type,  with  variations  such  as  a rotary^  maga- 
zine, two  of  which  were  found  in  an  arsenal  outside  of  Tokyo. 
7'hese  were  marked  i and  2,  respectively*.  Most  likely  they  were 
experimental  models,  and  they  may  liavc  been  the  only  two  made. 

However,  the  decision  of  the  Amiv  hoard  was  to  adopt  the 
Garand  .276  instead  of  the  Pedersen,  and  the  report  recommend  ins 
this  actinu  was  laid  on  tiK  Chief  of  Staff's  desk,  when  a sure  of  n 
figurative  atomic  bomb  burst  in  rhe  semi-automatic  rifle  business. 
General  Mac  Arthur,  U.  S.  Army  Chief  of  Staff,  disapproved  rhe 
report,  and  stated  that  rhe  recommendation  had  been  made  under 
a misapprehension;  there  would  be  no  change  in  the  caliber  of  the 
service  ammunition. 

This  decision,  which  as  proved  by  later  events  was  cniinentiy  sound, 
ended  the  many  years  of  work  on  the  .276  rifles,  and  required  a new 


i 

tt 

s 

It  « 

tirsi  model  ol  chc  present  .50  i^Uber  Ml  ri^lc.  Gar«ui<l  dtst  buili  suceOMv?  iiiodeh  of  primer  actuated  .30  cafil>«r  giicK.  then 
a .276  ga»  actuated  gun  ii>  lake  the  Pedersen  .276  cartridge.  The  gnn  shown  above  duplicates  his  .276  in  .30  caliber.  Photo  taken 
September  10,  1030 


lapancsc  cop>  of  the  1.  S.  Garand  Ml  ride.  Gnns  like  thiv  differing  from  ihe  l_.  S.  Ml  onlv  in  minor  deiails  were  found  in  xhe 
JiipancNe  service  towards  ihc  cime  of  the  war.  Main  dirferencej  were  the  caliber,  which  was  die  standard  Japanese  7. ‘mm;  the  rear  sight, 
which  was  of  the  ramp  tvpe,  and  the  rciagaaine,  which  was  .erraaged  foe  loading  by  having  the  c.trtridgcs  stripped  out  of  a clip  as 
is  done  in  the  M1905  Springfield, 


ThK  MiUIAKY  SFMIAtTOM.Vnt  RitLE  169 

Stan  Co  be  made  in  the  matter  of  the  selection  of  a semi-automatic 
shoulder  rifle.  Fortunately  Garand  had  already  been  working  on  a .30 
caliber  model,  and  he  proceeded  to  submit  it  for  test,  Twenty  of  these 
rides  were  snbTiiitced  for  service  test,  and  the  rifle  was  standardized 
Jan.  9,  1936,  as  the  U.  S.  Rifle,  caliber  .30,  M 1. 

Soon  after  this  an  allotcinenc  of  S8o,ooo  was  given  to  Springfleld 
arnmry  for  the  construction  of  80  of  these  rifles,  together  with  a 
ciHisideiabIc  amount  of  tooling  up  for  making  them  by  production 
merhods. 

The  first  actual  f]uantiry  pn)diicdon  of  parts  starred  at  Spring- 
field  Armory  in  January.  1937,  and  completed  rifles  starred  coming 
off  the  production  lines  in  August  of  the  same  year. 

During  World  War  II.  the  Garand  was  produced  by  the  Wim 
Chester  Repeating  Arms  Co.,  as  well  as  by  the  Springfield  Armory, 
a total  of  4,028,395,  being  produced. 

Johnson  v>*.  Gtitrand 

In  Cape.  .Melvin  jM.  Johnson,  C.S.1VI.C  Reserve,  started  work 
on  a 11  nidi  improved  type  of  shore  recoil  action,  which  he  incor- 
porared  in  both  a semiauromatic  rifle  and  a light  machine  gun.  This 
gun  Mas  ready  for  production  about  the  end  of  1939,  and  was 
adopted  by  the  Netherlands  Indies  Army  and  by  the  Royal  Nether- 
lands Navy. 

There  is  no  doubt  that  both  the  Johnson  Automatic  Rifle  and 
the  Johnson  Light  Machine  Gun  were  excclienc  weapons,  with 
many  attractive  and  useful  features.  Some  people  thought  that  we 
should  abandon  the  Garand  and  adopt  the  Johnson,  though  there 
was  nothing  to  show  that  the  Johnson  was  any  better  than  the 
(jarand,  or  for  that  matter,  as  good.  The  tooling  up  for  the  Garand 
has  been  completed  at  great  expense,  and  some  50,000  of  the  new 
guns  had  been  Jiianufacturcd.  so  that  even  if  the  Johnson  had  been 
better,  a change  at  that  time  was  out  of  the  question.  Finally,  ex- 
perience by  the  Marines  with  both  types  in  the  Southwest  Pacific 
demonstrated  the  fact  that  the  Garand  was  unquesrionablv  a better 
battle  rifle  than  the  Johnson.  The  Johnson  rifles  that  the  Marines 
had  acquired  were  turned  in  and  Garands  obtained  to  take  their 
place.  The  Johnson  is  nevertheless  a splendid  semiautomatic  rifle, 
and  OpCain  Johnson  is  entitled  to  a world  of  credit  for  his  out- 
standing accomplishment  in  developing  it  in  a very  short  time. 

Emopean  Sem/autov/at/cs 

Both  Gemianv  and  Russia  used  a certain  number  of  semi- 
automatic shoulder  rifles  during  World  War  II.  The  best  of  these 
is  probably  the  German  (Jewehr  43,  later  called  K-43. 

This  is  a gas  operated  gun,  with  a gas  piston  and  operating  rod 
lying  on  top  of  the  barrel,  under  a wooden  handguard.  Contrary 


Oech  ?-92  ZH'^T  setniauioiraiic  rifle  captured  in  Gernuny  duting  World  War  H. 


e A 


The  Mimiaky  Semiai:t(jmai k:  RtPLE 


171 

ta  usual  practice,  the  piston  is  the  fixed  member;  the  cylinder  is 
arranged  to  telescope  over  the  fixed  piston. 

The  gas  is  taken  off  ten  inches  from  the  chamber,  and  must  pass 
through  the  port  and  then  back  through  the  4 inch  length  of  the 
fixed  piston  before  it  comes  out  at  the  rear  of  the  piston  and  strikes 
the  moveable  cylinder.  Thus  the  action  of  the  gas  is  softened  con- 
siderably. 

The  locking  arrangcnicnc  comprises  two  wing-like  pieces  pivoted 
in  the  breech  block.  As  the  firing  pin  goes  forward,  it  wedges  these 
pieces  out  into  recesses  in  the  receiver,  thus  locking  the  action.  As 
the  gun  is  fired,  rhe  0|X.*rating  rod  is  driven  backward  by  the  gas, 
striking  the  l)olr  carrier,  and  driving  it  to  the  rear.  It,  in  turn,  pushes 
back  the  firing  pin,  first  camming  the  two  locking  wings  inward  and 
out  of  engagement  with  the  locking  shoulders,  then  carrying  the  bolt 
to  the  rear. 

1 have  seen  samples  of  this  gun  in  both  22  and  24 14  inch  barrel. 
'I'hc  longer  barrel  model  weighs  9 lbs.  07.  with  magazine,  and  is 
46%  inches  overall.  It  has  a ten  shot  detachable  box  maga/.inc, 
inserted  from  the  bottom.  It  has  a l>ase  for  telescope  mounting  on 
the  right  side  of  the  receiver. 

Previous  German  models  were  the  Gewchr  41,  the  Gew.  41  M,  and 
the  Gcw.  41  W.  These  were  operated  by  a piston  driven  to  the  rear 
hy  gas  action,  bur  there  wxs  no  gas  port  in  the  barrel;  instead,  there 
was  a irmzzlc  cap  over  the  end  of  the  barrel,  something  like  that 
used  by  Gar  and  on  his  first  gas  operated  modcU.  The  gas  is  trapped 
inside  this  cap  long  enough  to  act  <»n  ihc  piston.  In  the  Gcw.  41 
and  the  41  W,  the  breech  action  h almost  a duplicate  of  the  Gcw.  4^; 
the  Gcw.  41  M has  a turning  bolt  with  a straight-pull  acti<jn. 

The  Russian^  had  a Simonov  semiautomatic  in  1956,  called  A vs  56, 
which  was  both  semiautomatic  and  full  automatic.  It  was  ?as  operated, 
with  the  piston  and  gas  cylinder  on  top  of  the  barrel.  ‘1  he  lock  is  a 
h<dlow  rectangular  member  which  is  cammed  downward  out  of 
engagcnienr  with  the  breech  block  when  the  breech  block  carrier  is 
driven  to  the  rear  bv  the  backward  stroke  of  the  piston.  As  it  was 
intended  for  optinnal  full  niitoiiiatic  fire,  this  gun  had  a nniz/le  brake 
or  compensator  to  control  tl>c  cfinib.  rhis  vas  continued  on  the 
later  l okarcv  models,  (hough  the  full  automatic  feature  was  dropped. 

Follow'ing  the  Sinioncv  was  the  Tokarev,  Model  1938  and  later, 
Model  1940.  This  weapon,  the  invention  of  an  engineer  naincd  Feodor 
Vasily evirch  Tokarev,  is  a gun  of  neat  and  effective  design.  It  is 
chambered  for  the  regular  7.61  nun  cartridge,  and  is  fed  from  a ten 
shot  detachable  magazine,  inserted  from  rlic  bottom.  Tlie  magazine 
iiiav  also  be  clip  fed  while  in  place  in  the  gun. 

The  gun  is  gas  operated,  with  a gas  cylinder  on  top  of  the  barrel 
near  the  muzzle.  The  operating  rod  passes  through  a hole  in  the  rear 
sight  instead  of  straddling  it  as  in  the  Simonev. 


Another  >iew  of  jhe  Czech  ZH-3”  ^efniaiuotnacK'  rirte  found  in  Germany  in  World  War  II. 


A second  type  o(  Czech  cxpecimeocal  scmiautcfiiatic  ride  found  id  Getnun>  during  World  War  II.  It  is  ruade  in  ihc  regular  German 
7.92  caliber,  and  U gas  operated. 


German  semiautomaiic  rifles  oi  World  War  II:  I.  Gcwchr  4lM.  2.  Gcwchr  41W.  J.  Gewchr  43.  4.  Cewehr  43  with  stotk  r& 
moved  to  show  gas  c>'clindef 


y^pcrimemut  Carbine,  »booiinc  the  .45  caliber  9«mcc  auromaiic  piMol  cariridge,  made  ar  Springdeld  in  1921.  It  had 


inch 


't  f?  1 

■ 1»  MiiM  t 
• 

C.u  ;it*» 
'••m  KitUif. 

ft  a ff.  ijj 
''  ft  a.ii.tf' 

>ft  ft 


Tiu:  AIimtarv  Sfmi \iToM \ru'  Rim.i* 


177 


The  bolt  is  of  the  rocking  type,  biinibr  in  locking  principle  ro  that 
on  the  old  CoIl  iMadiinc  (iiin,  or  rhe  Winchester  VUhIcI  12  '^liorgun. 
As  the  bolt  carrier  intivcs  fnrwartl  imtler  the  acrion  i)f  rhe  return 
spring  in  dosing  rhe  action,  a cam  lips  the  rear  end  of  the  bole 
dtiwnward,  locking  it  in  fninc  of  a .shoulder  in  the  receiver.  As  the 
operating  rod  i.s  driven  to  the  rear  under  the  uii pulse  of  the  gas,  it 
pushes  the  bole  carrier  back;  this  action  cams  the  rear  end  of  the  bole 
up  out  of  engagement  with  the  shoulder  in  the  receiver,  thus  per- 
mitting it  to  he  carried  to  the  rear. 

The  gun  is  remarakably  light,  weighing  only  lbs.,  with  maga- 
zine. The  barrel,  including  the  integral  muzz.lc  brake,  is  27  inches 
long;  if  the  muz/.lc  brake  is  not  included,  the  length  is  24V2  inches. 
I'hc  overall  length  of  the  gun  is  4^  inches. 


The  C7.  S.  Orrhhte,  C*ii.  .]o  M / a fid  M j 

During  u;4o  the  Ordnance  decided  ro  produce  a very  liglu  semi- 
automatic rifle  to  rake  the  place  of  the  pistol  in  the  .armament  of 
c<»mpany  officer^,  noivcummissioned  oflicers,  communication  iinirs 
engineers,  tank  units,  artillery,  etc. 

The  cartridge  was  developed  in  conjunction  with  liie  Winchester 
Kepcating  Arnrs  Co.,  from  their  .u  self-loading  rifle  cartridge. 
It  has  a round  nosed  iio  grain  bullet,  driven  at  a muzzle  velocicv 
of  1975  f.s.  by  a charge  of  approximately  12.4  grains  of  Hercules 
(Jarbinc  Powder,  called  by  the  Army,  Hercules  Hake,  or  bv  a snip 
able  charge  of  rhe  Western  Cartridge  Compny’s  Hal]  Powder. 

The  gun  was  to  weigh  not  over  pounds,  and  \vas  to  be 
capable  of  either  semiautomatic  action  or  full  juitomatic  fire. 

An  Ordnance  test  in  1941  was  followed  by  a service  ie>i,  wliich  I 
was  fortunately  able  to  attend.  A numl>er  of  models  were  rested, 
su  bn  lie  ted  by  Springfield  Armoiy,  Winchester,  rhe  Auto-Ordnance 
Co.,  W’oodhull.  Hyde,  Savage  Anns  Co.,  and  Harrington  and 
Richardson.  The  Winchester  model  w,is  adopted  in  the  larrei*  pare 
of  1 94 1. 

T!ic  gun,  which  weighs  4V;  lbs.  and  has  an  overall  length  of 
inches,  with  an  18  inch  barrel,  has  a breech  iiicchniiism  like  that  of 
the  Garand,  operated  by  a short  stroke  piston  with  gas  take-off 
near  the  breech.  For  description  of  this  system  of  operation  see 
the  previous  chapter.  A modification  of  the  carbine  called  the  M t 
A I has  a folding  skeleton  stock  in  combination  with  a wooden 
pistol  grip,  to  lighten  the  gun  for  use  bv  parachute  troops. 

A further  modification  called  the  M 2 is  arrangctl  for  either  full 
automatic  or  sciiii-automaric  fire  at  the  option  of  rhe  user,  according 
to  rhe  position  of  a selecting  lever. 


'The  Military  Semialtomatic  Rifle 


J79 


European  C^rrbMes 

The  Germans  produced  a sn-callcd  Machine  Pistol,  the  MP  45, 
which  has  already  been  mcncioned  under  Subiiiacliine  guns.  This  is 
not  properly  either  a subinachin^iin  or  a machine  piscoX  but  instead 
is  a full  automatic  or  scmhanromatic  carbine,  arranged  to  shoot  a 
shortened  version  nf  the  7.9  111  ni  German  ser\dce  cartridge.  This 
was  by  a big  margin  the  most  advanced  European  weapon  in  the 
carbine  clafw. 

Another  gun  which  comes  closer  to  being  a carbine  than  a sub- 
machine gun  is  tlic  Italian  Berctta  Moschetto  or  little  vmsket.  This 
is  a carbine  shooting  the  9 mm  Parabelluni  pistol  cartridge. 


VII 

Experiments  With  Barrel  Obstructions 

There  arc  some  things  about  guns  and  slioocing  that  are  usually 
the  subject  of  hearsay  rather  than  of  accurate  first  hand  knowledge 
on  the  part  of  most  of  the  shooting  public,  and  one  of  these  is  the 
ciTect  of  the  various  abuses  that  arc  popularly  supposed  to  result  in 
a blown-up  gun. 

Perhaps  rlie  reason  is  chat  most  people  would  rather  hear  abnm 
trouble  than  expcrieiicc  it,  and  so  play  safe;  and  the  small  minority 
who  have  enough  curiosity  to  want  to  find  out  haven't  the  time  or 
facilities. 

It  happens  once  in  a while,  however,  that  snme  individual  is  so 
placed  by  circumstances  as  to  afford  him  an  opporrunicy  to  in* 
vestigate  some  of  these  things  without  too  much  trouble.  Thar  is 
just  what  happened  to  me.  One  thing  alone  that  would  guarantee 
me  an  opportunity  to  sec  a lot  about  how  guns  behave  is  the  fact 
rhiu  I have  been  cither  Ordnance  Officer  or  Ordnance  Technical 
observer  at  nearly  every  National  Match  that  was  held  between 
World  Wars  I aud  II. 

The  point  of  all  this  is  that  in  all  those  years,  I have  rarely  ever 
seen  a gun  failure  cause  any  injury  to  the  user,  and  what  few  injuries 
1 have  seen  could  mostly  have  been  avoided  by  the  use  of  shooting 

I have  tried  almost  everything  I could  think  of,  and  in  my  early 
shooting  days,  1 didn't  know  enough  to  wear  shooting  glas^,  but 
I was  lucky,  and  never  received  an  eye  injury.  Now  I wouldn't  fire 
a shot  with  any  kind  of  gun  without  shooting  glasses  on,  or  lacking 
special  shooting  glasses,  ordinary  eyeglasses  would  prevent  the 
majority  of  eye  in|uries. 

I have  seen  high  powered  rifles  blown  up  bv  all  kinds  of  fool 
tricks,  such  as  buying  a new  gun  and  then  firing  it  without  ever 
looking  in  the  barrel  to  sec  if  it  happened  to  be  full  of  cosmolinc*, 
getting  a cleaning  patch  stuck,  with  a rod  wedged  in  the  patch,  and 
then  tr}nng  to  shoot  both  rod  and  patch  ouc  of  the  gun  with  a ball 
cartridge;  loading  a ball  cartridge  with  blank  cartridge  powder, 
which  just  cannoc  be  confined  without  causing  a detonation;  etc. 

Lots  of  these  incidents  resulted  in  verv  narrow  squeaks  for  the 
perpetrator  of  the  stunt,  but  none  that  I have  witnessed  ever  really 
hurt  anyone.  Once,  for  example,  when  I was  in  charge  of  the  Ex- 
perimental Dcparcnient  at  Springfield  Armory,  we  were  trving  to 
develop  a blank  cartridge  attachment  for  the  service  .45.  The  .special 

iSo 


Experiments  with  Barrel  ODSTRrcrioNs  i8i 

barrel  had  a plug  in  the  muzzle  wicl\  a very  small  hole  in  ic,  and  the 
chamber  was  made  too  small  to  accept  a r^ular  ball  cartridge,  but 
would  take  the  special  blank.  'Fhesc  blanks  worked  all  right  when 
the  closing  wad  could  be  made  hard  and  brittle  so  it  would  break  up 
in  passing  through  the  small  hole  at  the  muzzle.  One  lot,  however, 
failed  to  dry  out  properly,  and  the  wads,  instead  of  being  brittle, 
were  giinmiy,  and  the  first  one  ch*»ked  the  vent.  I wa's  firing  at 
the  lime,  and  the  next  shot  with  that  sensitive  blank  powder  conhned 
in  the  barrel,  simply  detonated,  and  blew  the  barrel  and  slide  all  to 
pieces,  leaving  me  holding  the  handle  of  the  giiti  and  w ondering  why 
1 hadn’t  been  hurt. 

I certainty  don’t  want  the  statements  made  above  to  be  construed 
as  any  encouragement  to  take  chances  with  dangerous  overloads, 
ctc.j  anyone  who  keeps  on  with  chat  long  enough  is  sure  to  be  hurt. 
What  I do  mean  is  chat  if  you  take  reasonable  care  and  wear  glasses, 
your  chances  of  being  hurt  hy  your  gun  arc  slight.  Also,  when  you 
look  at  the  wrecked  guns  pictured  in  this  book,  remember  chat  most 
of  them  didn't  hurt  anyone,  after  all. 

Now  getting  to  the  subject  of  diis  chapter,  barrel  obstructions, 
I suppose  that  all  of  us  have  had  accidental  experiences  along  this 
line.  I remember  very  well  a certain  .iz  of  childhood  days  (the  clays 
when  cleaning  a gun  had  not  been  heard  of),  which  one  time  failed 
CO  bring  down  a sparrow  at  very  close  range;  not  only  that,  but  it 
failed  to  even  make  him  flv;  anS  still  worse,  the  whole  contents  of 
the  magazine,  shot  in  rtpid  succession,  did  not  obtrude  itself  on  his 
consciousness  in  anv  way,  or  produce  aj\y  visible  or  audible  result 
at  all.  The  puzzled  feeling  of  surprise  occasioned  by  this  umisual 
circumstance  prompted  an  in  vest  iga  cion  which  disclosed  the  nstonish- 
ing  fact  that  tlic  barrel  did  not  have  a hole  through  ic.  The  gun  was 
taken  to  the  village  bicycle  man,  who  acred  as  gunsmith,  locksmith, 
and  general  utility  man,  to  have  the  dozen  or  more  bullets  bored  out. 

The  operatiem  was  conducted  wdth  expediiiou  and  ccorujim  , and 
while  I have  never  inquired  into  how  he  conducted  the  burimj  tnic 
operation,  ur  how  he  gi>t  out  the  remnants  of  lead  that  miL*'hc  have 
remained  between  the  lands,  1 can  say  chat  the  result  was  entirely 
satisfactory  and  was  avcII  worth  the  quarter  it  cost,  and  the  old 
Winchester  is  still  kicldng  around  to  prove  it.  Of  course,  the  accunicy, 
measured  by  modern  standards,  h nil,  but  you  can’t  expect  much 
from  a barrel  that  has  endured  many  damp  summers  with  little  or 
no  cleaning.  The  incident  seemed  to  indicate  that  the  .11  show  hns 
not  power  enough  to  blow  up  a gun,  no  matter  what  vou  do.  Thi^ 
conclusion  encouraged  me  to  try  shooting  under  water  with  a .22,  an 
experiment  that  was  completely  satisfacturv.  The  gun  was  loaded 
entirety  under  water,  so  that  the  barrel  was  filled.  Good  practice 
was  had  at  tin  cans  some  ten  feet  away,  and  the  worst  damage  to 
the  gun  was  the  wetting. 


lidlian  Ber«cia  Mi>schcico.  or  carbine.  Nfodet  19  ^6*  A.  using  the  9nim  Parabelfum  care  ridge. 


HaTCIJER’s  NnTRIMH)K 


182 

Anoctier  incident  that  h equally  well  ijn pressed  on  my  memory 
refers  to  a time  sonic  years  ago,  when  I was  trying  out  for  a certain 
rifle  team,  and  another  member  of  the  squad  in  pisc<)l  pracrice  had 
the  side  of  the  cylinder  on  his  revolver  lifted  out  by  what  seemed 
to  be  an  extra  heavy  cxplosi^m.  Investigation  finally  shou  ed  that  the 
trouble  was  caused  by  a double  charge  of  powder  in  cl\e  cartridge. 
It  was  factory  loaded  stuff,  put  up  by  <uie  of  our  largest  makers, 
and  we  heard  a story  of  how  it  happened,  which  ran  this  way.  The 
machine  for  patting  in  the  powder  charge  was  arranged  to  handle 
fifty  cartridges  at  a Time.  Now  this  particular  machine  just  once 
made  two  strokes  instead  of  one,  thus  putting  a double  dose  of  powder 
into  all  fifty  of  the  shclU  of  that  batch.  When  the  lot  of  cartridges 
containing  these  fifty  bad  ones  got  onto  the  marker,  trouble  started 
for  both  the  revolver  makers  and  the  cartridge  company,  lor  soon 
complaints  began  to  come  in  from  widely  separated  points.  After 
several  such  eases  had  been  reported,  and  it  was  found  that  in  each 
ease  a revolver  had  blown  up  while  “A”  ammunition  of  lot  *‘J3”  was 
being  used,  the  company  realized  where  the  trouble  lay,  and  with- 
drew the  whole  lot  of  cartridges  from  their  dealers,  and  also  replaced 
all  The  revolvers  Thar  were  damaged  from  this  cause.  Incidentally, 
they  fi.xed  the  loading  machines  so  that  they  could  no  longer  put 
in  more  chan  one  load  uf  powder. 

I'he  damaged  revolvers  had  the  cylinder  wall  blown  our,  w'hich 
is  rhe  way  a revolver  fails  under  very  high  pressure.  Apparently  no 
personal  injuries  I'Csulred  from  any  of  these  blow-ups.  The  lessons 
of  this  inciJeiic  arc,  first,  that  a doiihic  charge  of  Bullscyc  doesn’t 
do  a revolver  any  good,  and  second,  that  an  overcharge  in  a revolver 
may  blow  out  the  cylinder,  but  cannot  injure  the  barrel.  Damaged 
barrels  result  from  ocher  causes.  For  example,  I once  knew  a young 
man  who  was  annoyed  one  night  by  an  owl.  He  was  an  excellent 
revolver  shot,  so  he  got  out  his  .45  Model  1917,  and  took  careful 
aim  by  the  bright  moonlight,  and  fired,  without  disturbing  his 
feathered  friend  in  the  least.  He  took  better  aim,  and  fired  again, 
and  when  the  owl  only  opened  his  big  eyes  and  looked  puzzled,  he 
took  a quick  shot  with  lots  of  temper  behind  it,  and  finally  threw 
die  revolver,  wliich  at  least  gave  him  the  satisfaction  of  seeing  the 
feathered  pest  flap  away  into  the  darkness.  When  he  icrricvcd  his 
gun  and  went  to  clean  it,  it  wouldn’t  clean,  and  on  examining  for 
the  reason,  he  found  chat  the  barrel  was  plugged.  A steel  drift  and 
a hammer  removed  three  service  bullets.  The  barrel  was  slightly 
bulged. 

Again,  I have  seen  a .58  military  model  revolver  with  the  barrel 
absolutely  full  of  bullets  (1  think  there  were  nine),  and  a .32-20  the 
same  way.  These  were  jacketed  bxillecs.  The  l^rrcls  were  sawed 
lengthwise  for  examination,  so  that  there  is  no  doxibr  char  the  bullets 
were  there.  The  .32-20  was  badly  bulged,  and  .38  only  slightly. 


Ex^kriments  with  Barrel  Obstrlctioks  i8j 

The  chances  arc  that  sucli  accidents  are  caused  by  a cartridge 
having  a weak  charge,  or  none  at  alL  Perhaps  in  some  cases  the 
powder  has  been  deteriorated  from  a trace  of  oil  that  in  some  way 
got  into  the  case  during  manufacture.  A weak  charge  might  drive 
the  bullet  only  part  way  into  the  barrel  of  the  revoher,  and  the 
next  bullet  would  be  stopped  by  the  obstruction. 

Many  cases  like  this  have  occurred  with  model  1917  revolvers, 
and  in  some  cases  the  barrels  are  .split  along  the  line  of  lettering 
“U.  S.  Property"’’  under  rhe  barrel,  which  forms  a weak  section.  As 
far  as  has  been  heard,  these  accidenrs  have  not  caused  any  injury  to 
persoimcl.  This  trouble  dues  not  seem  to  occur  with  the  automatic 
piscol.  Perhaps  it  is  because  the  barrel  of  the  pistol  is  closed  for  its 
whole  length,  instead  of  having  an  opening,  as  the  revolver  does 
between  the  barrel  and  the  cylinder,  which  would  allow  the  escape 
of  gas.  With  the  closed  barrel,  even  the  defective  charge  will  usually 
drive  the  bullet  clear,  and  thus  avoid  trouble  on  the  next  shot. 

If  the  head  of  the  cartridge  used  in  the  automatic  pistol  is  very 
soft,  it  is  possible  for  ic  to  blow  out  at  the  bottom,  w'hcre  the  barrel 
is  chamfered  to  permit  easy  feeding.  ‘I'his  may  split  ihc  grips  of 
the  pistol  in  (he  older  model  having  wooden  stocks.  With  the  steel 
ca  midge  cases  used  in  the  recent  war  this  ^^o^]d  not  happen. 

I have  rarely  seen  the  service  .45  pistol  badly  wrecked  by  an  acci* 
dent  in  service,  but  hnalty  one  came  in,  whici)  Is  shown  in  a picture 
with  this  chapter.  Ic  seemed  as  if  this  must  certainly  have  been  due 
to  a cerriffic  overload.  This  result  was  duplicated  experimentally  by 
a charge  of  Bullseyc  powder  of  nearly  three  times  the  pn)pcr  amount. 

1 have  already  mentioned  my  experience  with  the  blank  cartridge 
in  the  .4?.  The  barrel  had  no  locking  lugs,  so  that  the  pressure  could 
blow  the  action  straight  back,  anS  there  was  a choke,  or  plug, 
screwed  into  the  end  of  the  barrel  which  reduced  the  bore  at  this 
point  to  about  an  eighth  of  an  inch,  .so  as  to  confine  the  gas  and 
give  more  power  to  work  rhe  action.  A charge  of  about  five  grains 
of  blank  cartridge  powder  was  used,  which  worked  verv  well,  except 
when  the  choke  got  stopped  up  by  a wad.  The  first  time  this  hap- 
pened. a bulge  occurred  in  the  barrel,  at  the  front  end,  just  behind 
the  choke,  though  there  was  no  bullet,  only  powder,  and  the  place 
where  the  bulge  occurred  was  nm  the  weakest  part  of  the  barrel,  as 
there  was  a thin  section  over  the  chamber  which  was  not  nearly  as 
strong. 

Another  barrel  w'as  then  made,  and  it  was  tcmi>ercd  much  harder, 
rhis  time  when  the  wad  jammed,  the  barrel  split  wide  open,  blowing 
the  slide  off  ar  the  same  time,  but  leaving  the  grip  intact. 

Id  speaking  of  blank  canridges,  it  may  be  remarked  that  the  * E.  C. 
blank  cartridge  powder  used  in  this  test  burns  wdth  extreme  speed. 


E.  C..  for  “Explosives  Company.” 


Hatcher’s  Kotrb(x>k 


184 

The  reason  is  clear  when  ic  is  reiiieinbcrec!  chat  there  is  no  bullet  to 
confine  the  gas  and  cause  a report,  so  chac  reliance  must  be  placed 
on  a powder  that  will  bum  all  at  once  and  give  a sharp  report  even 
when  it  is  not  heavily  confined. 

This  question  of  blank  cartridges  brings  to  mind  the  case  of  an 
enrhu.siasr  who  once  got  hold  of  some  of  this  powder,  and  being 
fajDiliar  with  F,.  C.  Shotgun  powder,  failed  to  realise  that  E.  () 
Blank  cartridge  powder  Is  different,  and  loaded  a batch  of  shells  with 


Rffm  of  a h«4vy  overciu^e  of  Dull9C>e  powder  The  lower  pistul  was  blown 
up  in  service.  Spriag£«ld  Armory  dupUrac^  ihc  accidviH  by  usinp  a charge  of 
12  grains  of  BuUseye  instead  of  ibe  normal  iharga  of  about  4X*  grains.  A«  is  usual 
in  acxideais  tif  this  kind,  the  drer  was  not  io|urcd. 


this  fast-l) timing  scuff.  T'o  try  out  his  new  load  he  got  out  his  fine 
Lefever  gun,  and  ptir  up  a target  in  the  shooting  gallery  to  get  the 
pattern.  Some  of  the  lotingcrs  in  the  vicinity  >vere  watching,  and 
they  saw  him  swing  up  his  gun  and  fire.  'Fhere  was  a terrific  detona- 
tion, and  a big  piece  was  blown  out  of  the  side  of  rhe  barrel  near 
the  breech,  and  flew  across  the  room,  glancing  off  the  wall  and 
striking  a bench,  where  it  buried  itself  in  the  wood. 

I he  owner  of  the  gun  w as  an  inveterate  experimenter,  who  had 
gotten  into  trouble  once  or  twice  before.  Whether  the  shock  dazed 
him,  or  whether  he  felt  chat  he  had  better  hide  his  mistake  to  prevent 
his  friends  from  laughing  at  it,  will  never  be  known,  but  what  hap- 


EXPKRtMRNTS  WITH  R^RRF.L  O»STRl'Clt0NJ>  1S5 


This  shows  what  will  happen  if  the  charge  of  piMoI  powdec  is  increased  to 
about  three  tiows  the  oormal  amount.  Even  so,  there  is  not  much  danger  to  the 
hrcr. 


The  magic  rcrm  *' Nickel  ^(cel"  d<>e«  noi  mean  that  the  teceKer  caimoc  burse.  This  1917  hnficlcl  had  a cleaning  patch  wedged  in  the 
barrel  about  2 inches  in  front  of  the  chamber,  and  ihe  owner  tried  to  shoor  it  out.  The  top  of  the  receiver  was  blown  away,  but  Uie  boll 
remained  in  places  held  by  the  bottom  lug.  and  no  one  was  bun. 


Experiments  with  n.\RRFi.  Obstiu  ctions  187 

pened  is  chat  he  ac  once  put  on  an  indescribably  ludicrous  air  of 
unconcern,  as  if  he  were  perfectly  unconscious  that  anything  liad 
happened,  and  marched  down  the  room  bumming  a snatch  of  song 
and  swinging  the  gim  in  time  ro  the  tune.  Onickly*  and  with  a covert 
glance  to  be  sure  that  no  one  had  noticed,  he  slipped  the  gun  into 
his  locker  and  started  to  walk  off  to  another  part  of  the  room. 

But  this  would  never  snir  the  audience,  who  at  once  wanted  to 
know  “What’s  the  trouble?**  To  which  the  victim  replied  that  there 
was  no  trouble,  he  was  just  tired  of  shooting  for  a while.  When  his 
atreniion  was  drawn  rather  forcibly  to  the  piece  of  gun  sticking  in 
the  bench,  he  saw  that  he  hadn’t  gotten  away  with  anything.  lie 
blushed  and  stammered  as  he  admitted  that  there  muse  have  been 
an  accident,  and  tried  to  convince  his  now  thoroughly  anmsed  audi- 
ence that  he  hadn’t  noticed  it  before.  Tlic  material  lesson  of  this 
episode  is  plain.  Don’t  use  blank  cartridge  powder  behind  lead.  The 
psj'choingiral  lesscjn  is  not  $0  plain,  but  was  interesting  to  the 
observers. 

Machine  guns  are  a big  source  of  experience  in  the  behavior  of 
small  amis,  Tor  they  are  shot  so  much  that  many  things  can  happen. 
This  recalls  an  incident  on  the  Border  in  i^i^,  when  the  Ordnance 
Department  had  sent  some  I^wis  guns  to  the  troops,  and  they  were 
being  instructed  in  the  use  of  them.  A factory  expert  was  demonstrat- 
ing, and  had  just  fired  several  .shots,  when  the  gun  stopped.  He 
pulled  back  the  handle,  and  out  came  an  empty  shell.  1 called  to  him 
not  to  shoot,  but  he  had  already  pulled  Hk  trigger,  and  apparently 
nothing  happened,  for  the  gim  went  on  shooting,  but  when  it  was 
dismounted  that  evening  the  barrel  was  found  to  luve  a lump  on  it 
the  si?.c  of  an  egg.  Tlie  shot  that  failed  to  work  the  gun  Ivid  stuck 
in  the  barrel,  and  the  next  shot  had  caused  the  bulge.  Perhaps  the 
fact  that  the  barrel  was  surrounded  by  the  thick  aluminum  radiator 
had  kept  it  froni  bursting. 

As  was  mentioned  in  a previous  chapter  another  peculiar  incident 
occurred  with  the  Benei  Machine  Rifle,  when  a student,  who  had 
fired  the  gun  until  it  was  nearly  red  hot,  managed  to  get  the  breech 
mechanism  jammed  partly  open  with  a live  cartridge  in  the  chamber. 
Hoping  to  be  able  to  dislodge  the  carcri<^e  before  it  exploded  from 
the  hear,  I pushed  a ramrod  quickly  dowm  the  barrel  from  the  muzzle, 
and  just  as  the  rod  came  sharply  against  the  bullet,  the  cartridge 
exploded.  The  breech  was  open,  and  the  impact  of  the  heavy  rod 
prevented  the  bullet  from  moving  forward  as  long  as  the  cartridge 
case  was  perfectly  free  to  move  backwards.  The  result  wa.s  that  the 
cartridge  case  was  blown  out  of  the  breech  and  torn  to  bits,  without 
doing  any  harm,  while  the  bullet  remained  in  place. 

This  naturally  brings  up  the  question  of  what  would  happen  if 
such  a cartridge  were  extracted  from  the  breech  and  should  then 


Hatch  PR’s  Notebook 


m 

explode  from  the  hcac.  I have  seen  this  happen^  at?  most  people  have 
who  have  handled  the  old  air-cooled  machine  guns  to  any  large 
extent.  The  result  is  only  a very  nidd  explosion,  just  sufficient  to 
burst  the  brass  case  open  and  scatter  burning  grains  of  powder  around. 
The  reason  chat  the  explosion  is  not  more  violent  is  that  the  pressure 
necessary  to  rupmre  the  cartridge  case  is  not  sufficient  to  cause  the 
powder  to  burn  rapidly  enough  to  develop  its  full  force.  These 
accidents  are  not  very  dangerous,  except  for  the  possibility  that 
small  bits  of  brass  may  be  blown  into  the  eyes. 

A hang-fire  gives  a similar  result  when  It  occurs  after  the  cartridge 
has  been  entirely  ejected,  but  if  it  should  occur  just  as  the  holt  has 
been  unlocked,  and  while  the  cartridge  is  still  in  the  chamber,  the 
result  is  likely  to  be  serious,  as  the  pressure  will  be  lield  in  sufficient! v 
to  develop  a powerful  explosion,  which  may  blow  the  bolt  back  with 
violence. 

One  of  the  best  ways  to  become  act]  ua  in  ted  with  the  causes  of 
rifle  trouble  and  their  results  is  to  have  to  examine,  study  and  report 
on  the  various  damaged  rifles  char  arc  sent  in  from  the  service  from 
time  CO  rime  for  posc-murtcni.  On  two  separate  occa.sions,  once  before 
the  war  and  once  afeenvards,  I have  been  stationed  at  Springfield 
Armory  in  charge  of  the  experimental  department,  where  this  work 
is  done.  Many  of  the  wrecks  bore  eloquent  testiniony  to  the  destruc- 
tive power  of  the  improvised  cleaning  patch  and  the  unsuirahilicy 
of  the  old  Style  service  hat-cord  for  use  as  a puU-through.  The 
bac-cord  W'ill  pull,  hut  it  will  not  push,  and  when  a soldier  who  is 
trying  to  clean  his  gun  with  one  of  them  gets  it  all  the  way  into  his 
rifle  barrel  and  then  tries  to  dislodge  it  with  a cleaning  rod.  trouble 
starts.  No  matter  how  you  push  it,  the  w'oozy,  wobbly  thing  wedges 
together  and  cannot  be  moved  an  inch.  Of  course,  if  you  had  some- 
thing like  a corkscrew,  and  could  get  hold  of  the  end  to  pull,  it 
would  come  out  easily  enough,  but  ordinarily  no  such  object  is  ar 
hand,  and  some  friend,  with  a quick  but  not  cautious  brain,  sees  a 
way  out  of  the  difficulty,  and  sa>T>  “Let’s  shoot  it  out.”  “Of  course! 
Wny  didn’t  1 think  of  that  before?”  sav.s  the  owner.  In  goes  a 
cartridge,  the  trigger  is  pulled,  and  the  next  moment  the  air  is  full 
of  flying  splinters  of  the  stock,  and  after  the  victim  picks  himself 
up  and  looks  to  sec  if  he  is  all  there,  he  glances  at  his  rifle  and  finds 
the  barrel  split  and  the  rest  of  the  outfit  looking  pretty  sick  from 
the  blast. 

The  shirc-cail  cleaning  patch  is  another  trouble  maker.  The  rifle- 
man who  has  no  cur  patches  and  tears  off  an  irregular  piece  of  cloth 
to  sw'ab  out  his  rifle  often  finds  himself  in  a worse  fix  t!ian  he  would 
if  he  nude  no  attempt  whatever  to  clean  his  gun.  The  ill-fitting  piece 
of  cloth  requires  undue  force  to  push  it  through,  so  that  frequently 
the  cleaning  rod  pierces  the  patch  and  wedges  so  tightly  that  it  is 


Experjments  with  Barrel  Obstructioxs  189 

a problem  to  gee  it  out  at  all.  If  the  shoocii^-out  method  is  employed, 
the  results  arc  the  same  as  with  the  hat-cord,  only  more  pronounced. 

The  wrong  way  of  using  the  r^ular  cleaning  patch  may  also 
cause  trouble.  To  prevent  the  cleaning  rod  from  piercing  and  wedging 
it,  the  comer  of  patch  should  be  turned  over,  and  the  tip  of  the 
rod  should  be  placed  against  the  double  thickness.  If  this  is  not  done, 
hue  the  rod  is  merely  placed  in  the  center  of  the  patch  against  the 
single  thickness  of  cloth,  it  inav  punch  through  and  wedge, 

An  officer  in  charge  of  a company  on  the  firing  range  will  usually 
encounter  cases  where  men  will  get  obstructions  in  their  rifles  which 
cannot  be  removed  by  ordinary  methods.  A number  of  years  ago 
vvlien  in  charge  nf  a rifle  range,  I employed  a method  of  removing 
obstructions,  which  may  be  interesting,  though  for  reasons  whicfi 
will  appear  later,  it  is  distinct! v not  recommended  now.  I read  in  an 
old  Ordnance  manual  printed  in  the  days  of  muzzle  loaders  the 
results  of  a series  of  experiments  to  determine  the  effect  of  failing 
to  ram  the  ball  all  the  way  down  onto  the  charge  before  firing. 
The  early  experiments  tried  the  effect  of  pushing  the  bullet  ncar^ 
onto  the  charge  and  ring  the  piece.  The  pressure  was  found  to  be 
less  than  nonnal.  The  next  time  the  ball  was  i*animed  only  half 
way  down,  and  this  gave  a pressure  much  less  than  before.  La.stly, 
the  ball  was  inserted  near  the  muzzle  and  on  firing  a very  low  pres- 
sure was  recorded.  None  of  the  barrels  were  harmed  in  the  least  by 
these  experiment,  and  the  conclusion  was  that  firing  a gun  with  the 
bullet  not  entirely  seated  on  the  powder  could  not  injure  the  gun. 
But  when  two  balls  were  employd  at  one  time,  one  near  the  breech 
and  another  some  distance  away  in  the  barrel  the  gun  was  burst. 

This  iiifornwrion  seemed  to  indicate  that  if  m atrempr  were  made 
to  blow  out  an  obsmiccion  with  powder  gas  the  pressure  would  be 
less  than  with  a service  charge,  and  no  harm  would  result  if  the  bullet 
were  first  removed  from  the  cartridge.  After  a few  cautious  experi- 
ments along  this  line  I applied  this  method  as  will  be  described.  When 
a rifle  was  brought  up  with  an  obstruction  in  it,  I removed  the 
bullet  and  half  the  powder  from  a cartridge  and  then  holding  the 
muzzle  elevated  so  that  the  powder  would  stay  against  the  primer, 
I fired,  blowing  out  the  obstruction.  Success  was  uniform  for  the 
few  times  this  method  was  employed  during  several  seasons  on  the 
range.  Still  I always  had  some  misgivings  as  to  just  what  might 
happen  in  unusual  cases,  so  that  I was  quite  pleased  when  an  oppor- 
tunity was  presented  to  test  out  this  matter  thoroughly  under  proper 
experimental  conditions. 

The  first  question  taken  up  was  the  removal  of  rags  and  cleaning 
patches  stuck  in  the  barrel.  These  were  easily  blown  out  with  a 
cartridge  from  which  the  bullet  had  been  removed,  and  no  injury 
to  the  barrel  resulted.  Then  several  rags  were  tried  at  a time,  as  well 


Hatcher’s  Noikbook 


190 

as  patches  wedged  tightly  in  place,  but  alt  were  removed  without 
difficulty.  Next  we  cried  pieces  of  hat-cord  which  were  wetted  to 
make  them  stick  more  tightly-  When  these  were  successfully  re- 
moved it  began  to  look  as  if  the  method  would  prove  worthy  of 
recommendation  as  a standard  method  to  be  used  for  removing 
obstructions. 

Finally,  as  a last  grand  demonstration  as  regards  rags,  a cleaning 
rod  was  (lied  off  on  a j»lant,  and  with  it  a couple  of  patches  were 
wedged  tightly  in  place.  A cartridge  minus  bullet  was  then  inserted 
and  fired  with  all  the  confidence  in  the  world  that  the  cleaning  rod 
and  patch  would  go  flying  down  the  range,  but  strange  to  say  no 
such  thing  happened.  Instead,  the  only  result  was  a loud  prolonged 
hiss,  as  of  escaping  steam,  and  on  cautiously  opening  the  bolt  it  was 
found  that  the  powder  had  all  burned  up  without  moving  the 
ohstriiceion  in  the  least.  Also  it  was  noted  char  the  cartridge  case 
was  partly  filled  with  a thick  black  sludge,  or  mud,  the  residue  of 
the  powder  when  burnt  under  these  peculiar  conditions,  and  there 
was  an  acrid  smell  which  was  not  at  all  like  the  regular  smell  of 
powder  gas.  The  next  thing  that  was  tried  was  a heavier  charge 
of  powder,  all  that  could  be  put  into  a cartridge  case.  Result,  just 
the  same  as  before.  It  appeared  chat  with  the  regulation  powder, 
which  burns  slowly  like  celluloid  unless  closely  confined,  the  loosely 
woven  porous  cloth  patch  did  not  furnish  enough  resistance  to  make 
the  powder  burn  quickly,  so  that  the  pressure  leaked  our  as  fast  as 
ii  was  generated.  The  obvious  remedy  was  to  use  a quick  powder, 
such  as  Idack.  As  a can  of  King’s  semi-smokcless  was  close  ar  hand, 
a shell  full  of  ir  was  tried  without  success.  Then  a cartridge  full  of 
fine-grained  black  powder  was  used  which  finally  blasted  the  ob- 
stmetion  loose,  without  injury  to  the  barrel.  After  this  experience 
the  method  did  not  look  quite  so  good. 

The  next  thing  tried  was  dislodging  bullets  stuck  in  the  barrel.  It 
was  found  that  a bullet  lodged  at  any  point  was  easily  blown  out. 
using  the  futf  charge  of  powder.  This  experimenr  w'as  tried  on  an 
old  discarded  pressure  gtin  and  it  was  found  tluit  the  pressures  ran 
very  much  less  than  nonnal,  as  would  have  been  cx|KCtcd,  especially 
after  reading  the  old  experiments  referred  to  above.  When  the  bullet 
was  seated  at  rhe  muzzle,  the  pressure,  with  a cartridge  case  full  of 
powder,  was  aboxit  half  scr>'icc  pressure.  No  swelling  or  other 
injury  to  the  barrel  could  be  detected. 

These  resxilrs  did  not  indicate  any  danger  in  this  procedure,  but 
there  has  been  talk  of  tl»c  possibility  char  gas,  in  rushing  down  the 
barrel  at  high  speed  and  being  suddenly  arrested  at  the  base  of  the 
stationary  bullet,  miglit  pile  up  at  this  point  and  expend  its  dxmamic 
energy  in  a local  ring  of  pressure  that  would  nor  show  on  the  pres- 
sure gage,  hut  would  still  be  capable  of  doing  damage.  To  try  out 
this  idea  a bullet  was  wedged  tightlv  inro  rhe  muzzle  so  that  ir  would 


Expjvkimek  js  with  Barrrl  Obstructiox.s  191 

offer  considerable  resi<;tance  to  being  expelled.  Then  the  gun  was 
loaded  and  the  trigger  was  pulled,  but  11  ci thing  happened;  nor  even  the 
hissing  chat  had  been  experienced  with  the  tighcljr  wedged  rags.  We 
wondered  w'hether  it  was  a misfire  or  w'hether  the  cartridge  had  gone 
off  and  all  the  gas  was  remaining  penned  up  in  the  barrel  ready  to 
come  out  with  a bang  as  soon  as  the  breech  was  opened.  In  order 
to  avoid  casualties  we  pointed  d^e  breech  in  a safe  direction  and 
opened  the  bolt  by  tapping  the  handle  with  a piece  of  wood.  No 
sooner  w'as  the  bolt  handle  driven  to  a vertical  position  than  the  bolt 
suddenly  flew  open  with  a loud  “pop*'  like  a champagne  cork,  and 
the  empty  shell  w'as  ejected  smartly.  As  the  obstruction  had  not  been 
removed  a heavier  charge  was  tried,  then  a mixture  of  black  and 
smokeless,  without  success,  chough  with  plenty  of  fan  opening  the 
bolt  each  time.  Finally,  after  two  tries  with  black  powder  the  bullet 
was  blown  out,  but  on  examination  the  muzzle  of  the  barrel  was 
found  to  be  slightly  swelled.  It  was  hard  to  cell  just  w'hac  had  caused 
the  swelling,  for  if  the  piling  up  of  a gas  pressure  at  this  point  had 
done  it,  it  would  seem  that  the  swelling  would  be  found  just  behind 
the  bullet.  In  fact  it  was  at  the  very  end  of  the  muzzle,  almost  at  die 
front  end  of  the  wedged  bullet! 

Ihc  only  thing  that  this  test  settled  was  the  fact  that  more  rests 
were  needed  to  enable  proper  conclusions  to  he  drawn  as  to  just 
what  was  happeiiiug.  It  was  therefore  decided  to  go  ahead  and  do 
some  of  the  things  chat  usually  cause  damage,  so  as  to  dc  ten  nine 
exactly  how'  the  various  forces  produce  their  effect.  We  knew  that 
firing  out  an  obstruction  with  a bullet  usually  results  in  disaster,  so 
the  next  experiments  were  planned  to  show  more  plainly  just  what 
happens  in  this  case. 

The  first  thing  tried  was  the  effect  of  loose  drops  of  water  in  the 
barrel,  as  might  happen  in  case  of  rain.  No  effect  could  be  detected. 
Apparently  the  mass  of  the  water  drops  does  not  check  the  bullet 
enough  to  do  damage.  Next,  small  pieces  of  brass,  such  as  are 
punched  from  the  vent  holes  of  cartridges  in  manufacture,  were  laid 
in  the  bore  in  front  of  the  bullet  in  the  position  that  might  be  oc- 
cupied in  case  one  of  these  punchings  should  be  left  in  the  cartridge 
in  manufacture  (as  sometimes  happens),  and  dioiild  follow  the  ballet 
a sliorc  way  down  the  bore  in  faring,  and  then  lodge  and  wait  to 
cause  a disturbance  on  the  next  shot.  These  punchings,  singly  or 
several  at  a time  did  not  cause  any  trouble  that  could  be  detected. 
It  seems  clear  that  they  cannot  bulge  or  burst  a barrel  with  the 
present  service  rifle  and  cartridge.  After  this  an  investigation  of  the 
effect  of  bullet  jackets  lodged  in  the  barrel  w'as  undertaken.  It  was 
found  that  they  always  caused  a slight  bulge  in  the  barrel.  In  one 
case  the  new  bullet  passed  completely  through  the  lodged  jacket, 
and  in  so  doing,  pressed  it  slightly  into  the  .steel,  so  that  it  could  not 
be  dislodged.  After  this  a number  of  other  bullets  were  fired  without 


19^  HaTCHFR’s  NOTH3O0K 

moving  the  lodged  jacket,  which  became  bedded  down  into  the 
metal  of  the  bore  so  that  it  could  hardly  be  seen  from  tlie  inside. 
In  being  pressed  into  the  sted,  it  raised  a slight  bulge  In  the  barrel, 
which  could  be  detected  from  the  outside. 

Cleaning  patches  lodged  loosely  in  the  barrel  gave  a very  slight 
bulge,  or  none  at  all,  but  two  heavy  patches  jammed  tightly  in  place 
gave  a large  bulge,  and  if  the  barrel  had  happened  to  be  a seamy  one, 
it  would  probably  have  split  from  end  to  end.  A light  piece  of  paper 
placed  loosely  in  the  barret  gave  no  effect. 

These  results  suggested  very  forcibly  the  question,  “Just  what 
causes  a bullet  to  ring  a barrel?*’  Some  people  say  with  great  con- 
fidence that  it  is  the  pressure  of  the  air  which  is  suddenly  compressed 
between  the  moving  bullet  and  the  stationary  obsmicrion.  This  theory 
seems  extremely  unlikely.  Then  ocher  thwrists  sav  thai  checking 
the  huliet  as  it  strikes  the  obstruction  causes  the  rapidly  moving 
column  of  gas  to  be  arrested  suddenly  on  the  base  of  the  bullet,  so  that 
it  spreads  out  sideways,  changing  its  dynamic  energy  into  static  pres- 
sure which  is  momentarily  exerted  in  a ring  of  local  pressure  which 
may  cause  the  swelling.  Tliis  theory  is  better  than  the  first,  but  still 
it  does  not  seem  good  enough.  It  is  more  likely  chat  the  *'ring'*  seen 
so  often  in  a barrel  which  has  been  fired  with  an  ob.scruccion  is  due 
entirely  to  the  bullet,  as  a rough  calculation  will  show*  that  at  any 
point  in  the  barrel  the  moving  bullet  possesses  about  twelve  rimes  as 
much  dynamic  energy  as  the  rushing  gas  behind  it.  The  bullet  is 
made  ot  a plastic  material  of  very  great  density.  If  the  forwar<i 
motion  of  the  front  end  of  this  rapidly  moving  boiler  is  suddenly 
checked  the  inertia  of  the  lead  in  the  rear  portion  of  the  bulict, 
coupled  with  the  pressure  of  the  gas  on  its  base,  will  cause  it  to 
“upset/’  or  expand  sideways,  which  is  what  I think  must  cause  the 
ring.  Any  obstruction,  such  as  a patch,  cause.s  the  point  of  the  buller 
to  wedge,  and  thus  checks  it,  and  the  resulting  ring  is  proportional 
CO  the  amount  of  the  checking  effect. 

It  was  argued  that  if  this  theory  were  true  no  bulge  would  be 
caused  in  shooting  out  a cleaning  patch  or  other  light  obstruction, 
provided  that  the  wedging  could  be  prevented.  To  try  this  out  it  was 
decided  to  lodge  a rag  in  the  bore  and  then  shoot  it  out  with  a buller 
which  was  square  in  front  and  did  not  have  anv  pointed  end  to 
wedge.  The  quickest  way  to  do  this  seemed  to  be  to  use  the  back 
end  of  a regular  bullet,  so  one  was  palled  out  of  the  cartridge  and 
put  in  again,  back  end  forward,  and  a rag  was  shot  out  without  a 
sign  of  a bulge,  w'hich  may  be  taken  as  an  indication  in  confirmation 
of  the  wedging  theory,  though  it  is  of  course  by  no  means  con- 
clusive. 

After  this  experiment  with  ngs,  k was  decided  to  cry  the  same 
thing  with  bullets  as  obstructions,  to  see  what  could  be  learned  or 
deduced.  A bullet  was  lodged  in  a condemned  barrel,  near  the  muzzle. 


Experiments  with  Barrel  Obstructions 


*93 

and  a regular  cartridge  was  inserted  and  fired,  with  the  inevitable  re 
suit;  the  barrel  for\^^ard  of  where  the  bullet  was  lodged  was  blown 
completely  away.  It  was  not  possible  to  tell  w’h ether  the  damage 
originated  just  at  the  location  nf  the  obstructing  bullet,  or  behind 
it,  as  the  barrel  was  to*i  completely  destroyed  at  this  point.  Ac  least 
one  thing  was  certain,  though,  and  that  was  that  this  attempt  to 
shoot  out  a bullet  with  an  nr  her  one  caused  terrible  havoc.  In  order 


to  see  if  the  wedging  effect  had  anything  to  do  with  it,  the  experiment 
was  repeated  with  the  remaiiiiDg  portion  of  the  same  barrel,  and 
the  bullet  in  the  cartridge  was  revereed,  as  described  above,  so  as  to 
attempt  to  sweep  out  the  stationary  bullet  without  allowing  any 
wedging  effect.  As  was  expected,  the  result  was  the  same  as  if  the 
bullet  had  been  shot  sharp  end  first;  the  barrel  was  '‘.saw^ed  off,”  so 


to  speak,  at  the  point  of  obstruction.  There  is  really  no  contradiction 
between  this  result  and  the  one  obtained  when  the  rag  was  shot  out 
successfully  with  the  square  end  of  the  bullet,  for  in  the  last  expert 
ment  the  mass  of  the  stationary  bullet  was  sufficient  to  cause  the 
lead  of  the  two  bullets  to  expand,  merely  from  the  impact,  without 
the  necessity  of  any  wedging  effect  to  help  the  action  along. 

In  this  connection  it  sh^ouTd  be  noted  that  in  all  the  experiments 
conducted  with  light  obstructions,  such  as  cleaning  patches,  etc.,  even 
where  everything  possible  was  done  to  make  the  conditions  favorable 
for  the  greatest  damage,  the  worst  results  obtained  were  rings  or 
bulges,  wTiilc  with  heavy  obstructions,  the  destruction  was  complete. 

To  determine  more  <!cfinircly  whether  or  not  the  gas  pressure  on 
the  base  of  the  bullet  had  anything  to  do  with  the  damage,  another 
experimenc  was  decided  on.  A plug  of  cotton  waste  was  put  in  the 
center  of  a condemned  barrel,  and  some  melted  lead  was  poured  in 
so  as  to  form  a slug  about  four  inches  long  at  about  die  middle  of 
the  barrel’s  length. 


On  firing  the  gas  was  all  retained,  as  has  been  described  before. 
This  firing  was  repeated  once  or  twice,  w'hen  to  our  great  interest 
a distinct  bulge  was  observed  at  about  the  middle  of  the  space  oc 
cupied  by  the  lead  slug.  Measurements  showed  that  the  lead  had 
not  moved.  In  attempting  to  account  for  the  formation  of  the  bulge 
at  this  point,  it  was  thought  possible  that  the  lead  might  have  been 
poured  in  so  as  to  leave  cavities  or  vacant  spaces  which  would  give 
the  effect  of  two  or  more  slugs  separated  by  a certain  space,  which 
could  be  driven  together  by  the  force  of  the  explosion,  and  thus 
ring  the  barrel  as  two  bullets  would  when  driven  together.  To  elim- 
inate this  possibility,  as  well  as  to  verify  the  result  of  the  experiment, 
the  test  was  repeated,  taking  great  care  to  pour  the  lead  so  as  to 
form  a solid  obstruction,  without  cavities  or  pockets.  On  firing,  the 
ring  again  occurred,  which  would  seem  to  indicate  that  the  bulging 
of  barrels  is  principally  due  to  the  upsetting,  or  .sidewise  expansion 
of  the  lead  in  the  bullet.  The  hammering  of  the  gas  pressure  on  the 


IlATciiiiRs  Notebook 


'94 

base  of  the  lead  plug  is  what  caased  the  upsetting  in  this  case,  which 
leads  to  the  conclusion  that  in  firing  a bullet  with  an  obstruction  in 
the  barrel,  the  gas  pressure  on  the  base  of  the  bullet  aids  the  wedg- 
ing effect  in  causing  the  bullet  to  tipset  snfiicicndy  to  ring  the  barrel. 

During  World  War  I an  officer  of  the  Ordnance  Departinent  con- 
ducted a series  of  experiments  ar  one  of  cite  big  coiiiiiiercial  rifle 
plants  to  determine  the  effect  of  various  barrel  obstructions.  These 
experiments,  which  w^ere  made  wkh  1917  model  rifles,  should  prove 
very  instructive.  Ac  the  time  these  rests  were  made,  there  was  a lot 
of  trouble  with  loose  bullets  in  service  cartridges,  and  it  some  times 
happened  that  when  a gun  w^as  unloaded  without  firing,  the  case 
would  be  extracted,  but  the  bullet  would  stick  fast  in  the  rifling. 
It  was  feared  that  if  this  should  happen  on  a misfire,  and  another 
cartridge  should  he  inserted  and  fired,  the  rifle  would  he  blown  up 
from  the  effect  of  the  two  bullets. 

It  was  found  that  in  no  case  could  a bullet  without  any  cartridge 
be  forced  into  the  rifling  far  enough  to  allow  the  insertion  of  another 
cartridge  and  the  closing  of  the  bolt.  I lowevcr,  a bullet  was  inserted 
in  this  manner,  and  a cartridge  was  prepared  by  forcing  the  bullet 
down  info  the  case  uiuH  the  base  01  the  bullci  rested  liard  on  the 
powder,  filling  practically  all  the  air  space  and  projeciing  our  of  ihc 
cartridge  case  only  about  thrce-siwcenchs  of  an  inch.  This  prepared 
cartridge  was  inserted  in  a rifle  behind  the  .stationary  bullet  and  fired 
without  damage  to  the  rifle,  dxiugh  the  cartridge  case  showed  evi- 
dence of  exces.s  pre$.surc,  as  the  primer  was  blown  and  the  cartridge 
base  was  distorted. 

A bullet  was  driven  into  the  rifling  just  far  enough  to  permit 
another  cartridge  to  be  inserted  and  the  bolt  to  be  dosed.  On  firing 
both  bullets  were  ejected  without  damage  to  the  gun,  bur  the  case 
showed  evidence  of  high  pressure. 

A bullet  was  seared  in  the  barrel  with  the  base  one  inch  ahead  of 
the  point  of  the  bullet  in  the  cartridge  seated  in  the  chamber.  On 
firing  both  bullets  were  ejected  without  apparent  damage  to  the 
barrel. 

A bullet  was  then  seated  in  the  barrel  at  a point  one  inch  further 
aliead  than  the  one  just  described,  or  so  that  the  base  was  two  inches 
ahead  of  the  point  of  the  bullet  seated  ia  the  chamber.  On  firing 
the  barrel  wa.s  burst  from  the  receiver  to  the  lower  band. 


In  a barrel  and  action  without  stock,  a hiillct  wis  forced  into  the 
rifling  to  a point  one  inch  forward  of  die  lower  band  and  a cartridge 
was  inserted  Into  the  chamber.  On  firing  the  barrel  was  split  into 
three  sections. 


A bullet  was  seated  in  the  barrel  at  a point  one  and  three-fourths 
inches  from  the  muzzle.  On  firing  the  barrel  was  bulged  badly  at 
the  point  of  obstruction  and  the  part  forward  of  the  bulge  was  split 
into  four  parts. 


Hatcher’s  Note  rook 


196 

A dry  cleaning  patch  was  inserted  one  and  one-half  inches  in  the 
imiEEle.  On  firing  no  apparent  damage  was  done. 

A dry  cleaning  patch  was  inserted  to  a point  three  inches  to  the 
rear  of  the  lower  band.  On  Jlriag  the  barrel  was  split  from  the  re- 
ceiver to  above  the  lower  band  and  the  lower  part  of  the  stock  and 
the  lower  hand-guard  were  blown  away.  The  front  sight  carrier  was 
blown  entirely  off. 

A cleaning  patch  of  cotton  cloth  soaked  with  oil  was  rolled  up 
and  inserted  in  the  niu/^le  for  a length  of  about  one  and  a half 
inches,  as  it  would  be  in  the  case  of  a man  inserting  a plug  or  tompion 
in  his  piece  to  keep  out  the  dirt  or  rain  and  forgetting  to  remove  it 
before  firing.  On  firing  the  muzzle  was  split  about  one  inch,  the 
front  sight  carrier  was  blown  entirely  off  and  the  muzzle  was  slightly 

A cleahing  patch  soaked  in  oil  was  made  into  a roU  and  pushed 
into  the  bore  to  a point  about  the  lower  hand.  On  firing  a decided 
bulge  was  made  at  this  point,  which  is  visible  on  the  outside,  but 
there  was  no  rupture  of  the  barrel. 

The  piece  having  been  fouled  by  firing  a few  shots,  the  muzzle 
was  inserted  in  sand  and  then  shaken  out,  leaving  a very  small  a;nounc 
of  sand  or  dirt  in  the  muzzle.  On  firing  no  visible  result  was  produced. 

The  same  test  as  the  preceding  one  was  again  made,  leaving  a 
greater  amount  of  sand  in  the  muzzle.  No  effect  was  evident. 

One  inch  of  sand  was  insertetl  in  the  muzzle,  forming  a solid  plug. 
On  firing  the  sand  was  blown  out  without  apparent  effect. 

The  test  just  described  was  repeated,  putting  one  and  one-half 
inches  of  sand  in  the  muzzle.  On  firing  the  barret  was  split  in  two 
pieces  tu  below  the  lower  hand,  blowing  away  the  forward  end  of 
stock,  handguard  and  front  sight  carrier. 

The  barrel  was  filled  with  warm  cosinoline  and  allowed  to  drain 
naturally  for  a few  moments,  and  the  gun  was  then  fired  without 
cleaning.  No  damage  whatever  was  apparent  to  die  rifle  or  cartridge 
case. 

The  barrel  was  filled  with  warm  cosinoline  and  allowed  to  cool 
over  night,  leaving  a maximum  of  cosmoHne  in  the  barrel.  On  firing 
no  effect  whatever  was  visible  on  cither  the  barrel  or  the  cartridge 
case. 

A fairly  heavy  dose  of  cold  cosmolinc  was  distributed  through 
the  barrel,  not  enough,  however,  to  fully  obstruct  it  at  any  one 
point.  On  firing  no  effect  was  vi.sible. 

The  muzzle  was  filled  solid  with  cosnioline  to  a depth  of  approxi- 
mately one  inch.  On  firing  the  barrel  was  split  in  two  pieces  to  below 
the  upper  band,  and  the  front  sight  carrier  was  blown  entirely  off. 

A small  wad  of  chewing  gum  w^as  inserted  in  the  muzzle,  as  on 
inspection  a number  of  instances  have  developed  w'here  a man  has 
put  a wad  of  gum  in  the  muzzle  of  his  rifle  and  it  was  desired  to 


Experiments  with  Bakkli.  Obstructions  197 

see  what  would  result  if  such  a Avad  should  be  left  in  while  firing. 
A decided  bulge  was  caused,  ime  no  fracture. 

A study  of  the  experiments  that  have  been  descril)cd  will  ar  least 
partly  remove  this  siihjcrt  from  the  ronlin  of  conjecture  and  will 
often  enable  the  observer  to  tell  from  the  examination  of  a wrecked 
gun  the  general  cause  of  the  trouble  and  will  also  enable  one  to 
know'  what  to  expect  under  certain  circumstances.  For  example, 
some  years  ago  a new  front  sight  cover  and  protector  was  designed, 
which  consisted  of  a cup -shaped  steel  scamping  arranged  to  slip  over 
[he  front  end  of  the  gun  and  protect  both  the  muzzle  and  front 
sight.  A rifleman,  on  being  shown  the  design,  objected  that  it  would 
burst  the  barrel  if  the  shooter  foi^ot  to  remove  it  before  shooting. 
In  order  to  prove  it  the  gun  was  fired  with  the  muzzle  cover  on, 
with  the  expected  result,  which  was  chat  the  bullet  pierced  the  cover 
neatly  and  then  proceeded  on  its  way  with  no  harm  done  to  rhe 
rifle.  In  this  case  it  could  be  stated  with  certainty  chat  the  ride 
w'ould  not  be  injured  becaase  it  wa.s  known  that  tlie  service  bullec 
could  pierce  a one*sixteench-inch  piece  of  sheet  sreel  with  such  ease 
that  it  would  not  be  checked  serioasly,  and  if  the  bullet  were  not 
checked  the  barrel  would  not  be  harmed.  Thus  besides  having  an 
academic  interest,  experiments  of  (his  tiamre  give  the  designer  re 
liable  infontintion  that  is  at  times  invaluable. 


VIII 

The  Strength  of  Military  Rifles 

ONE  September  day  ui  1910,  1 happened  to  be  standing  on  the 
firing  line  at  Camp  Perry  during  a match,  when  the  competitor 
directly  in  front  of  me  fired  a Uioc— and  then  couldn’t  see  his  rear 
sight!  He  rubbed  his  eyes  increduioiisly,  and  looked  again,  then  let 
out  a howl  that  brought  me  to  his  side.  It  happened  that  I was  the 
Ordnance  Officer  of  the  Matches,  and  thus  was  responsible  for  the 
condition  and  performance  of  the  issue  National  Match  rrfie  he  was 
using.  What  was  this  about  no  rear  sight?  1 dropped  to  juy  knees 
beside  huii  and  cook  a look.  No  rear  sight  at  all— not  even  tlic  sight 
base,  but  in  the  newly  exposed  barrel  where  the  sight  had  been,  a 
nice  crack  about  an  inch  or  more  long.  Then  we  began  finding 
little  bits  of  the  sight  tying  around.  It  lud  broken  into  a dozen  or 
more  pieces,  the  breaks  occurring  on  the  lines  that  formed  the 
range  graduations. 

So  we  issued  him  a new  rifle  and  sent  die  damaged  one  back  to 
Springfield  for  the  investigation  that  was  always  made  whenever 
a rifle  failed  from  any  cause.  This  one  was  due  to  a hidden  scam  in 
the  mccal  of  which  the  barrel  had  been  made. 

Of  the  danmged  rifles  which  were  returned  to  Springfield  when 
1 was  in  charge  of  the  Experimental  Department  in  1917,  and  later, 
when  I was  Works  Manager  in  1919,  '20  and  ’21,  a fair  per  cent 
showed  barrel  failures.  ThU  might  lead  naturally  to  a question 
whether  the  barrel  is  properly  designed  as  to  strength,  so  let’s  look 
further  into  this  subject. 

Before  any  barrel  is  accepted  for  service  it  is  pronf  fired  with  a 
high  pressure  test  cartridge,  or  “blue  pill,”  w'hich  gives  about  forty 
per  cent  higher  pressure  than  the  service  load.  These  test  cartridges 
are  tin  placed  to  make  them  look  different  from  the  regular  cartridges, 
and  this  gives  them  a bluish  white  color,  hence  the  name  ‘‘blue  pill.” 
When  I was  at  Springfield,  the  regular  service  load  gave  a pressure 
of  around  50,000  pounds  per  square  inch,  and  the  blue  pill  at  first 
gave  70,000  pounds;  which  we  later  raised  to  75,000  pounds,  as  will 
be  explained  further  along. 

Each  finished  rifle  was  given  one  high  pressure  proof  charge,  and 
this  was  followed  by  five  service  loads  to  test  the  functioning. 

It  would  seem  that  this  test  should  eliminate  any  barrel  with  a 
tendency  to  weakness  of  any  kind;  but,  as  we  have  seen,  even  National 
Match  barrels  can  burst  in  service.  What  is  the  explanation? 

As  was  stated  above,  every  gun  that  failed  in  service  was  returned 

198 


Thf  Strength  of  Military  Rifles 


199 

to  Springfield  for  examination,  which  almost  always  showed  clearly 
the  cause  of  the  failure. 

The  object  of  rhts  examination  was,  of  course,  to  correct  any 
faulty  methods  or  design  features  that  might  be  responsible.  When, 
as  was  true  in  a large  number  of  cases,  the  barrel  showed  a decided 
annular  bulge  or  ring  near  the  origin  of  the  fracture,  there  was  not 
much  the  Armory  could  do;  the  damage  was  plainly  due  to  an 
obstruction  in  the  bore. 

A large  and  heavy  obstruction,  such  as  a bullet,  will  often  make 
a lump  as  big  as  a walnut,  and  may  split  the  barrel  to  pieces  in  ad- 
dition, while  a small  or  light  obstruction,  such  as  a cleaning  patch, 
may  leave  a hardy  perceptible  ting. 

As  inriiimrcd  above,  the  barrel  docs  not  always  burst  when  it  is 
fired  with  an  obstruction  in  it,  though  it  generally  docs  if  the  ob- 
struction is  a solid  object. 

Twice  I have  seen  a machine  gun  fired  with  a bullet  already  in  the 
bore,  and  in  neither  of  these  cases  did  the  bared  biirsr.  In  one  ease 
the  accident  was  not  even  discovered  until  several  hundred  additional 
shots  had  been  fired  and  though  a laigc  lump  had  been  formed  on 
the  barrel,  the  functioning  or  the  accuracy  were  apparently  nut 
affected. 

I have  seen  a Springfield  rifle,  which,  chough  it  had  a pronounced 
Inilgc  near  the  nuw/Jc,  still  shoe  very  well  indeed. 

Besides  obstructions  there  arc  two  other  occasional  causes  of 
barrel  failure.  One  of  these  is  seamy  metal  Before  any  machine  work 
is  done  on  the  barrels  they  come  to  the  factory  in  the  shape  of 
billets  of  steel  which  arc  afterward  heated  and  rolled  to  the  ap- 
proximate shape  of  the  barrel  In  this  barrd  steel  as  in  any  other 
metal,  flaws  will  occur.  When  the  pieces  of  barrel  steel  are  rolled 
out  to  a long  shape  to  make  the  barrel  blank,  any  flaws  that  they 
may  contain  arc  also  .stretched  out  in  the  same  direction,  so  that 
instead  of  a bad  spot,  we  get  a bad  streak. 

Most  of  tiiese  streaks  arc  discovered  during  the  machining  opera- 
tions. After  every  turning  operation  on  the  outside  or  reaming  opera- 
tion on  die  inside,  the  barrels  are  carefully  inspected,  and  any  with 
flaws  are  thrown  out.  Once  in  a great  while,  however,  it  happens 
chat  a seam  or  flaw  may  be  entirely  inside  the  walls  of  the  finished 
barrel  Luckily,  the  high  pressure  test  eliminates  most  of  these  barrels. 
Some  which  the  flaw  docs  not  gready  weaken  may  stand  the  high 
pressure  test  and  get  into  the  service.  Then  if  by  using  grease  on 
the  neck  of  the  cartridge,  or  bv  improper  handloading,  or  in  some 
other  wav  an  excess  pressure  Is  obtained,  the  barrel  inav  fail 

Another  trouble  that  was  experienced  after  World  War  I was 
burnt  steel.  Before  the  war,  the  billets  of  steel  were  rolled  into  barrel 
blanks  at  Springfield  Armorv.  But  during  the  production  rush  of 
1917  and  191ft  outside  sources  were  called  on  to  do  this  work,  and 


RcsuJi  of  a hidkten  in  ihc  barrel.  After  the  adoption  ia  1918  of  a double  heat  tfeatmeot  for  the  receiver  and  bull.  ii  was  the 
practice  to  select  a rifle  usoi>ionalh’  from  production  and  subject  it  to  the  higbcsi  pressure  that  could  be  obtained  in  a test  cartridge, 
lliis  ride,  selected  at  random  from  production  on  bfay  3.  1916,  was  first  tested  with  ten  7Q,0UU  pound  test  shots,  then  was  fired  with  a 
125.000  pound  teat  cartridge.  The  receiver  and  bolt  held,  as  they  invariably  did  with  (his  double  heat  treatment,  but  the  hidden  seam  in 
the  barrel  opened  up.  with  the  results  shown. 


201 


The  SxfeENcrH  of  Military  Rifles 

the  barrel  blanks  were  bought  from  the  steel  makers  already  forged 
to  shape.  These  factories,  instead  of  rolling  the  barrel  blanks  to  the 
finished  shape,  as  Springfield  did,  took  bars  of  steel  which  were  of 
the  right  diameter  for  the  main  part  of  the  barrel  blank  and  formed 
the  enlarged  breech  end  by  heating  this  part  of  the  l>lank  very  hot 
and  then  upsetting  or  bumping  up  the  large  part. 

In  order  to  get  quantity  production,  a great  many  of  these  blanks 
were  heated  at  once,  and  in  order  to  make  them  forge  up  easily  and 
ijuickly,  they  were  made  good  and  hot.  For  tliis,  as  well  as  all  ocher 
work,  the  steel  companies  had  to  contend  with  the  shortage  of  skilled 
help  chat  was  felt  everywhere  during  that  War,  as  well  as  during  the 
recent  one.  Under  such  conditions  it  was  natural  that  once  in  awhile 
a piece  was  left  too  long  in  the  furnace  and  became  too  hot. 

When  steel  becomes  too  hoc,  the  fine  crystalline  structure  that 
gives  it  its  strength  becomes  ruined,  and  the  metal  separates  into 
large,  coarse  gnins  with  a gaseous  film  between  them  which  takes 
away  their  power  nf  cohesion  and  makes  the  steel  w'cak  and  brittle. 
This  condition  is  very  hard  to  detect,  because  burnt  steel  looks  like 
any  other  steel,  and  in  aiiromaric  machinery  any  difference  in  the 
machining  qualities  could  not  be  noticed.  If  j»uclj  a blank  should  be 
made  up  into  a barrel  and  pass  the  proof  test  it  might,  from  the  re- 
peated shock  of  firing,  gradually  get  worse  in  service  until  a break 
occurs. 

Of  course,  this  condition  only  occurs  in  an  extremely  small  per- 
centage of  the  blanks;  perhaps  one  in  two  or  three  thousand,  and 
most  of  these  arc  detected  by  inspection  or  fail  on  proof.  That  the 
danger  from  this  cause  is  small  is  evident  from  the  tact  that  though 
all  guns  manufactured  at  Springfield  Armory  immediately  after 
World  War  1 had  barrels  made  of  this  steel,  several  ycai's  pa^d  be- 
fore a barrel  failure  occurred  which  led  to  the  d^»c*>verv  of  this 
condition. 

As  there  w'cre  several  hundred  thousand  barrel  blanks  on  hand  at 
the  end  of  the  War,  it  meant  that  all  barrels  to  be  made  for  a long 
time  had  to  be  made  from  this  steel.  How^ever,  once  the  trouble  Avas 
understood,  every  possible  step  was  taken  to  prevent  any  defective 
barrels  from  being  sent  out.  For  the  sake  of  greater  safety,  Spring- 
field  raised  the  proof  chaise  to  75,000  pounds,  instead  nf  70,000,  to 
be  more  certain  of  eliminating  all  faulty  barrels. 

In  the  course  of  experiments  on  receivers  some  years  ago,  I used 
pressures  up  to  130.000  pounds  without  any  apparent  ill  effects  on 
the  barrels.  The  late  Sir  Charles  Ross,  whom  I knew  well,  had  cold 
me  about  his  experiments  on  the  thickness  of  barrels,  and  I had 
read  .some  remarks  by  Newton  on  the  same  subject,  but  I couldn’t 
sufficiently  authentic  facts  to  satisfy  me,  so  I collected  some  first- 
hand infoiiiiation  by  turning  a Springfield  barrel  ro  r/8  inch  waU 
thickness  and  firing  it  with  regular  and  high  pressure  cartridges.  As 


202  Hatcher’s  Noteboor 

the  results  were  not  visible,  I turned  the  barrel  down  so  that  it  was 
only  i/n5  inch  thick  over  the  chamber.  It  held  rhrec  regular  service 
cartridges  perfectly.  T then  put  a 75,000  pound  shoe  through  which 
blew  a piece  out  of  the  side,  as  can  l>c  seen  in  the  photograph.  As 


t 

Tht  up^r  barrel  was  eurned  dtmn  uniil  h was  reduced  to  the  shown.  Three 
rej^lai  service  charges  were  bred  with  00  effect,  hut  a *’0,000  pound  blue  pill 
(high  pressure  test  t^tridge),  lifted  out  a piece  as  shown.  Ltiwer  barrel  is  for 
comparisoQ  to  show  size  before  toy  meul  was  removed. 


the  thickness  of  the  regular  barrel  at  this  point  is  5/16  of  an  inch, 
it  is  plainly  evident  that  the  strength  should  be  sulBcient. 

Failures  ifi  the  Action 

Now  that  we  have  disposed  of  the  barrel,  lets  consider  the  action. 
I once  received  a letter  in  which  the  writer  inquired  about  the 
strength  of  the  bolt.  He  stated  that  he  had  read  in  a magazine  that 
the  Springfield  bolt  was  much  weaker  than  that  of  the  Krag-Jorgen- 
scii,  and  char  the  Springfield  holt  was  dangerous  because  of  a tendency 
to  blow  out  of  the  rifle,  which  the  Krag  would  not  du.  Of  course, 


203 


I’he  StRENcrru  op  Mii.itary  Rifles 

anybody  who  has  any  conception  of  rifle  construction  knows  that 
cither  the  Springfield  bolt  or  the  Enfield  bolt  with  double  lugs  is 
far  stronger  than  the  Krag  boh  with  only  one  lug. 

Even  so,  the  Krag  has  entirely  satisfactory  strength  for  the  range 
of  pressures  for  which  it  was  dWigned,  that  is,  about  4(>,(X)o  pounds 
maximum.  In  connection  with  its  loading  of  Krag  cartridges,  the 
Ordnance  Department  derennined  chat  the  pressures  should  never  be 
allowed  CO  go  over  42,000  pounds  per  sc]iiare  inch. 

These  guns  have  been  used  by  many  persons  with  little  regard 
for  this  iiniitation,  and  consci|uemly  we  occasional!  v sec  a Krag  with 
one  locking  lug  cracked,  or  even  broken  entirely  off;  other  Krag  bolts 
have  broken  in  two  just  back  of  the  locking  lug.  However,  these 
bolts  did  not  blow  out  of  the  gun;  there  is  a rib  on  the  right  side 
of  the  bolt  chat  bears  gainst  a shoulder  on  the  receiver,  and  this 
acts  as  a safety  lug,  and  in  addition,  the  bolt  handle  turns  down  into 
a .doc  lit  the  rear,  which  acts  as  a further  safety  feabirc. 

The  Krag  rifles  have  been  in  use  since  October,  TK94,  whcit  the 
first  issue  of  the  so-called  Model  of  1892  was  made.  During  the 
intervening  period  of  over  50  years  this  fine  rifle  has  made  a great 
reputation  for  itself. 

The  1917  Enfield  will  occasionally  shed  its  lugs.  One  such  ease 
came  to  my  acccnrion  in  March,  1947.  Tlie  bolt  had  both  lugs  cmcked 
entirely  oft,  bur,  as  usual,  stayed  in  the  gun.  The  cartridge  showed 
every  evidence  of  extreme  pressure,  and  was  covered  with  a spotty 
black  deposit  of  caked  material  which  indicated  that  perhaps  it  had 
been  covered  with  grease  when  fired,  which  would  readily  account 
for  the  high  pressure.  The  owner  sent  along  the  damaged  bolt  and 
the  cartridge  ease,  accompanied  by  a letter  which  stated  in  part: 

. This  shot  blew  the  holt  and  locked  it  in  the  gun  sn  that 
we  couldn’t  get  the  empty  shell  out.  On  taking  it  down,  we  found 
the  holt  had  blown  apart;  that  is,  two  pieces  had  blown  off  the 
shell  extractor  end.  It  looks  to  me  like  a person  could  have  been 
hurt  if  the  bolt  could  have  come  out.  . . 

While  I don’t  believe  the  writer  of  the  letter  intended  it  as  ironical, 
rhe  last  sentence  is  certainly  a magnificent  understatement.  Fortu- 
nately for  him  the  bolt,  as  nsually  happens,  was  held  in  place  in 
spite  of  the  loss  of  its  lugs. 

For  a good  many  years  most  of  the  rifles  damaged  in  service  were 
returned  to  Springfield,  and  as  far  as  I know,  no  one  has  ever  seen 
a case  where  the  bolt  was  actually  blown  out.  I have  heard  people 
speak  of  cases  where  the  “bolt  blew  out**  but  investigation  or  closer 
^luestioning  has  always  shown  that  the  statement  was  not  accurate. 
1 have  never  been  able  to  run  down  one  authentic  case.  In  some 
of  the  low  numbered  Springficlds,  made  before  the  heat  treatment  was 
revised,  lugs  have  been  Imown  to  crack  off,  but  in  all  cases  the 
safety  lug  kept  the  bolt  from  actually  coming  back. 


204 


Hatcher’s  Notebook 


Just  how  strong  the  lugs  really  arc  in  relation  ro  their  normal 
load  was  very  well  shown  by  an  experiment  1 made  at  Springfield 
some  years  ago*  The  lugs  of  the  bolt,  which  have  a standard  length  of 
four-tenths  of  an  inch,  were  reduced  to  one-half  diac  amount,  and 
firing  tests  were  conducted  with  both  service  cartridges  and  high 
pressure  loads  with  no  bad  ctfccts,  I'lie  lugs  w'ere  then  reduced  in 
thickness  to  one-tenth  of  an  inch,  or  one-fourth  of  their  original 
dimensions.  Shots  with  service  cartridges  caused  no  trouble,  but 
a 75,000  pound  blue  pill  broke  ulT  the  weakened  lugs.  Still,  the  safety 
lug  held,  and  the  bolt  did  not  move. 

This  test  indicates  that  the  logs  on  the  bolt  are  about  four  times 
as  strong  as  necessary  to  hold  the  service  cartridge.  Still,  this  test 
did  not  satisfy  us.  We  thought  we  might  as  well  find  nut  exactly 
what  the  safety  lug  would  do  by  itself,  so  we  took  another  bolt 
and  removed  both  lugs.  I'hc  service  shot  crushed  the  safety  lug 
slijhrly,  but  did  not  move  the  bolt.  The  high  pressure  shot  sheared 
off  the  metal  nf  the  safety  lug  which  was  already  crushed,  and  al- 
lowed the  bolt  ro  move  tack  slightly.  However,  the  holt  did  not 
move  far,  for  the  safety  lug  sheared  oft  at  an  angle,  and  the  remaining 
part  wedged  under  the  right-hand  wall  of  the  receiver,  bringing  the 
holt  to  rest  after  it  had  moved  back  about  half  an  inch.  If  a bolt  with 
the  locking  lugs  entirely  removed  requires  a blue  pill  to  move  it  half 
an  inch,  the  regular  bolt,  with  all  its  lugs,  must  be  pretty  safe. 

The  Strength  of  the  Receiver 

The  next  subject,  and  perhaps  the  most  important  one  of  all,  is 
the  strength  of  the  receiver.  A broken  receiver  makes  a bad  mess, 
and  once  in  a while  w*e  do  see  cases  of  this  kind.  It  was  in  the  spring 
of  1917  that  I first  came  actively  into  contact  wdth  the  question  of 
receiver  strength.  I had  just  come  to  Springfield  Arniorv  from  the 
Mexican  border,  and  had  been  placed  in  charge  of  the  Experimental 
Department,  where  one  of  my  first  duties  was  to  examine  two  burst 
rifles  and  report  on  the  cause  of  the  trouble.  Both  rifles  had  failed 
while  using  a certain  make  of  wartime  ammunition.  This,  on  the  face 
of  it,  painted  tu  defective  ammunition  a$  the  cause  of  the  trouble, 
but  only  a cursorv  examination  of  the  steel  in  the  receivers  was  re- 
quired  to  show  that  it  was  coarse  grained,  weak  and  brittle.  I re- 
ported that  soft  cartridge  cases  had  probably  contributed  to  the 
failure,  but  that  the  real  underlying  cause  was  poor  steel  in  the 
receivers.  At  first  this  report  was  received  with  skepticism.  It  was 
argued  that  the  Springfield  rifle  had  been  used  for  years  with  no 
complaints,  and  that  as  both  accidents  had  occurred  with  the  same 
amnntnirion,  the  cartridges  were  to  blame.  The  answer  to  this  was, 
that  aside  from  any  fault  in  the  cartridges,  the  steel  was  susceptible 
to  a very  considerable  inqu'oveiiiau,  which  sliould  be  made  in  order 
to  give  the  rifle  the  greatest  possible  factor  of  safet}%  even  with 


The  STRr.NCTH  o^*  Mii  hary  Rifles  205 

bad  carcridges.  Finally  this  view  prevailed;  the  Armory  obtained  the 
services  of  a highly  skilled  metal  1 11  igisc  and  a staff  of  assistants,  and 
completely  revised  the  heat  trcaniieut  of  the  receiver  and  bolt,  as 
will  be  described  in  detail  later  on.  Meantime,  as  Chief  of  the  Ex- 
perimental Depaitmeuc,  ( proceeded  to  find  out  all  that  I could 
about  receiver  strength  and  related  matters. 

One  of  our  first  steps  was  to  try  the  effect  of  soft-headed  car- 
tridge cases.  To  do  this,  \vc  took  out  the  bullets,  powder,  and 
primer  from  a number  of  carcridges  and  annealed  the  heads  of  the 
cases,  thus  making  the  brass  vtry  soft.  We  then  reloaded  these  cases 
and  fired  them. 

VVe  found  chat  they  were  more  dangerous  than  the  high  pressure 
cartridges.  When  they  were  fired,  these  soft-headed  cases  would 
spread  out  at  the  back  end,  or  give  way  entirely,  letting  the  gas  at 
high  pressure  out  into  the  reedver,  with  disastrous  results.  When  gas 
at  50,000  pounds  is  pressing  on  the  iaside  of  the  barrel,  it  docs  not 
have  much  surface  to  work  on,  and  the  total  load  is  not  great,  but 
when  it  gets  out  into  the  bolt- well  of  the  receiver,  whose  diameter  is 
about  an  inch,  it  has  more  surface  to  push  against,  and  the  total  load  is 
enormous.  A failure  of  this  kind  may  burst  a weak  receiver,  and 
even  if  the  receiver  is  not  in|urcd,  escaping  gas  is  likely  to  do  damage 
of  ufher  kinds,  such  as  blowing  off  the  extractor,  splintering  the 
stock,  or  blowing  out  the  magazine  floor  plate.  An  extreme  case  of 
this  nature  occurred  with  soft  cartridge  case  in  a 1919  National  March 
rifle  in  which  the  receiver,  bolt  and  barrel  were  too  strong  to  be 
injured,  but  the  stock  was  badly  splintered. 

Besides  soft  cases,  we  cried  the  effect  of  high  pressures.  As  the  rifles 
were  constructed  at  that  time,  the  average  gun  would  stand  about 
80,000  or  90,00  pounds,  but  1 ioo,ooo  {>ound  shot  could  be  pretty 
well  depended  on  to  burst  the  receivers  of  almost  any  of  the  rifles 
then  coming  off  the  production  line 

One  thing  made  evident  bv  these  tests  is  the  fact  that  the  weakest 
feature  of  most  modem  militar)'  actions  is  in  the  cartridge  case  it- 
self. In  the  Springfield  rifle  the  head  of  the  cartridge  case  projects 
out  of  tlie  rear  end  of  the  chamber  a distance  of  from  .147  to  .1485 
inch;  In  other  words,  there  is  a space  of  well  over  an  eighth  of  an 
inch  where  the  pressure  is  held  in  only  bv  the  brass.  This  is  the  weak 
point  of  the  M 1903  Springfield,  the  M 1947  Enfield,  the  M 98 
Mauser,  and  other  high  powered  rifles  usinq  rimless  carcridge.s. 

When  very  high  pressures  are  encountered,  this  brass  wall  either 
spreads  or  blows  out,  and  the  gas  under  high  pressure  gets  loose  and 
wrecks  things.  If  the  receiver  is  weak  or  brittle,  it  may  be  fractured; 
if  it  is  strong,  then  the  extractor  mav  be  blown  off,  the  magazine 
well  may  be  bulged,  the  stock  may  be  splintered,  and  other  damage 
may  be  done. 

In  the  design  of  the  U.  S.  Rifle  Cal.  .30,  Mr.  Mr.  Garand  took 


206 


Hatcheh^s  Noteboos 


great  pains  to  eliminate  rhis  source  of  weakness  by  arranging  the 
rear  end  of  the  chamber  and  the  front  of  the  bolt  so  tliat  the  metal 
of  the  cartridge  case  is  surrounded  right  down  to  the  extractor 
groove  by  the  chamber  walls. 

In  spite  of  the  fact  that  there  were  over  four  million  Garand  M» 
rifles  made  during  World  War  II,  there  has  never  yet  been  a case 
reported  of  a blown  receiver  or  bolt  on  this  rifle.  It  is  true  that  as 
a result  of  firing  grenades,  the  rear  wall  where  the  bole  is  arrested 
in  its  backward  stroke  has  cracked  ouc  in  a few  instances,  but  there 
has  never  at  this  writing,  (June,  1947)  been  a case  reported  where 
the  receiver  has  failed  at  the  front  end  where  ilie  locking  is 
accomplished. 

In  trying  to  determine  the  uidmacc  strength  of  the  gun,  Mr. 
Garand  built  up  progrcswvcly  higher  proof  loads  in  increments 
of  5000  pounds  pressure,  from  the  regular  proof  load  of  70,000  lbs. 
CO  the  extreme  figure  of  120,000  lbs,  per  square  inch. 

Ac  this  latter  figure,  cracked  left  lugs  on  tl^c  bolt  began  to  be 
encountered.  A gun  in  which  the  bolt  had  the  left  lug  cracked  by 
ojie  of  these  excessive  high  pressure  overloads  was  men  fired  an 
enduranace  test  of  5000  rounds  of  service  ammunition,  using  the 
cracked  bole,  which  showed  no  further  deterioration.  The  U.  o.  Mi 
Rifle  thus  has  perhaps  the  strongest  action  of  any  military  shoulder 
rifle  in  existence  at  t^is  time. 

The  M 98  Mauser  and  the  Model  99  (^9J9)  7*7  Japanese  rifle 
arc  safer  than  the  Springfield  in  this  regard,  because  in  each  of  these 
guns  the  supporting  metal  of  the  chamber  conies  ro  the  forward 
edge  of  the  extractor  groove  instead  of  leaving  some  of  the  actual 
cartridge  case  wall  hanging  out  in  the  air,  as  do  the  Springfield  and 
Enfiela 

The  Krag,  which  uses  a rimmed  case,  docs  not  have  this  w'eakness. 
The  case  enters  the  chamber  right  up  to  the  rim,  and  there  is  little 
chance  for  the  cartridge  to  fail  at  the  head.  That  is  the  main  reason 
why  we  never,  or  at  least  hardly  e\'cr,  hear  of  a burst  Krag  receiver. 
A nearly  similar  condition  is  true  of  the  Japanese  Model  (1905) 
6.5mm  Arisaka  rifle.  It  uses  a semi-rim  cartridge,  which  has  only  a 
very  slight  extractor  groove,  and  the  cartridge  head  is  thus  quite 
strong.  As  the  cartridge  walls  arc  also  particularly  well  supported 
near  the  head,  the  action  of  this  rifle  is  harder  to  wTeck  than  those 
of  the  Springfield,  Enfield,  or  Mauser,  all  of  which  u?e  the  truly 
rimless  cartridge  with  its  weaker  head  constnictitm. 

S<??m  Rf^asofis  for  Cartridge  Failures 

As  has  been  stated  above,  the  modem  military  bolt  action  rifle  is 
no  stronger  than  the  cartridge  case;  or  stated  another  way,  the  first 
thins  to  fail  is  usually  the  case. 

A serious  weakness  in  poorly  made  cases  is  softness  of  the  metai 


The  Strengto  of  Military  Kift-fs  207 

near  the  head  of  the  cartridge.  Brass  gets  soft  when  it  is  heated,  or 
annealed;  and  it  gets  hard  when  it  is  worked.  In  order  to  be  able  to 
draw  the  brass  from  sheets  into  long  tubes,  it  is  heated  and  thoroughly 
softened.  After  the  tubes  are  drawn,  the  head  must  be  hardened. 
This  is  done  in  the  process  of  giving  it  its  final  shape,  during  whicli  ^ 
process  the  metal  must  How  into  the  shape  given  it  by  the  dies.  Forc- 
ing the  primer  pocket  into  the  solid  iiietaT  aids  considerably  in  the 
hardening  or  working  process.  Anorlicx  tiling  that  helps  is  imprinting 
tlie  lettering  chat  gives  tlie  make  and  date.  1 remember  in  one  series 
of  cartridges  where  we  wanted  the  heads  particularly  strong,  to  hold 
SO)  lie  high- intensity  loads,  we  carefully  changed  to  bigger  and  deeper 


Gkriridgc  case  with  longuudioal  spUc  in  bead  and  rear  end  o(  body. 
Note  the  o6f-cenier  position  ol  ibe  ring  crimp  around  ibe  primer.  The  mse 
was  not  held  centrally  00  the  snpporiin^  stem  during  the  ptuner  crimping 
operauoo,  and  the  crimpuia  pun^  struck  harder  on  one  aide  than  on  the 
other,  thus  OTer*streasiAg  the  metal  on  the  high  side,  and  making  it  too 
bud  and  brittle.  The  prevaleoie  id  this  defea  in  cases  of  1934  Frankford 
Arsenal  manufacture  led  co  a study  which  revealed  the  caxise  and  led  to  a 
correction  of  the  process  to  avoid  a cecurreoce. 

The  case  Illustrated  was  seat  in  April  24,  1947,  after  the  text  describin/; 
such  defects  bad  already  $ooe  cc  press;  thus  it  furnished  excellent  confirma- 
tion of  the  previously  wrineo  material. 

The  shooter  reported  thai  he  got  "quite  a blast  of  hot  gas/*  but  as  he 
was  wearing  sboocing  glasses,  he  was  not  aopured. 


lecwrs  scamped  on  the  hcad»  and  gained  quire  a bit  of  additional 
hardness  and  strength  this  way. 

After  the  head  is  formed,  the  cartridges  under  process  of  niann- 
facrure  must  be  heated  again,  $0  that  the  body  can  be  tapered  and 
the  neck  formed.  This  heating  is  often  performed  with  the  head  of  the 
case  standing  in  water,  so  that  it  cannot  absorb  heat  and  thus  be- 
come softened.  If  one  of  these  should  by  some  accident  during  manu- 
facture have  the  head  heated  after  it  is  formed,  the  head  may  spread 
and  the  primer  pocket  open  out  during  the  stress  of  firing,  and 
damage  to  the  gun  may  result.  Thus  in  cartridges  a soft  head  is  a 
dangerous  defect. 

Another  defect  that  is  quite  dangerous  is  a longitudinal  split  in 
the  body  of  the  case.  The  rear  end  of  the  case  is  rather  thick,  and 
the  rear  end  of  the  chamber  is  made  a little  loose,  so  that  cartridges 
can  feed  and  extract  easily.  The  thin  front  of  the  cartridge,  that  can 
expand  and  hug  the  walls’  of  the  chamber  is  depended  on  to  keep  the 
gas  in.  Tf  the  case  should  split  near  the  back  end.  where  the  metal 
IS  too  thick  to  hug  the  walls  closely,  gas  will  come  back,  and  if 


20S 


HATnHFR*s  NcrrKm>oK 


CAUBLR.30 


' •i^^UNT.  r:  i'lXTTv'E  KANUr  ACTURE 
. -o  iMPESri-'!;  ri  r CkA  a_ANK 


OtA/fK 


i 

s 

\ 

4 

y 

> 

• 

> 

4 

✓ 

> 

Photograph  made  a<  FrankforJ  Arseaal  lo  show  how  a slight  nick  in  thg  ^Usc 
from  whiih  a cartridge  is  drawn  oia)  cause  a bculy  split  in  the  finished  enrtridge 
when  it  ia  fired.  The  rick  is  more  pronounced  in  Series  1 and  decreases  in  the 
others. 


the  i; hooter  is  no:  wearing  glasses,  serious  eve  injury  may  result. 
Always  wear  shoocii^  glasses! 

In  well  made  cartridges,  this  defect  of  a longitudinal  body  split  is 
not  very  common;  but  at  one  time  Franlcford  Arsenal  was  having 
t]iiite  a bit  of  trouble  from  this  cause,  \faster  Mechanic  Andrew  H. 
Hallowell  undertook  to  find  out  wh\  the  condition  was  occurring, 
and  he  finally  traced  it  to  the  fact  that  w’hcn  the  discs  from  which 


The  STRrsoTH  of  MruTARy  Rifles  209 

the  cartridges  are  made  were  being  cue  from  tlie  sheet  brass,  they 
%vere  spaced  too  closely  together,  so  that  occasionally  there  was  a 
bit  of  overlapping,  and  the  edge  of  one  of  the  discs  might  be  nicked 
slightly. 

“Andy”  found  that  when  this  occurred,  the  nicked  place  caused  a 
tiny  crack  that  extended  some  distance  down  along  the  side  of  the 
drawn  cartridge  case,  and  sometimes  opened  up  under  the  pressure 
of  bring.  This  is  shown  in  the  photo  made  at  the  time  from  blanks 
chat  were  found  to  have  a slight  piece  cut  out  of  the  edge. 

As  soon  as  the  cause  of  this  trouble  was  found,  ir  was  of  course 
eliminated  but  some  time  later,  the  same  defect  cropped  up  again. 
This  time  it  was  found  that  the  presses  had  been  speeded  up  in  an 
effort  to  gain  more  production  per  day;  evidently  if  the  cases  were 
drawn  too  fast,  the  metal  was  worked  and  hardened  more  than  was 
good  for  It,  and  becan^  brittle.  When  the  presses  were  returned  to 
their  former  slower  pace,  the  trouble  usiia  disappeared. 

Once  more,  however,  the  defect  of  lengthwise  splits  in  the  rear 
part  of  the  cartridge  case  body  appeared,  this  time  in  the  ipu 
.30  caliber  M i hall  ammunition.  Once  more  the  shop  “detectives^' 
were  put  on  the  trail  to  find  out  why-  After  some  cases  were  cue 
up  and  micro -photographs  were  made  it  was  seen  that  on  one  side 
the  brass  crystals  were  smaller  than  they  were  on  the  other  side, 
indicating  harder  brass  there.  It  was  also  seen  that  the  metal  of  the 
head  was  thicker  on  that  side.  Cases  that  had  not  yet  had  the  primers 
crimped  in  did  not  show  the  streak  of  hardness  down  one  side. 

It  was  finally  determined  that  the  crimping-in  of  the  primer  was 
responsible  for  making  a streak  of  hardness  down  one  side  of  the 
cases  tliat  sometimes  gave  wav  in  the  form  of  a crack.  In  crimping-in 
the  primers,  the  cases  arc  held  on  a stem  which  acts  as  an  anvil  for 
supporting  the  case  against  the  crimping  punch.  When  one  side  of 
the  head  was  thicker  than  the  other,  this  sup^Hirting  stem  made  con- 
tact with  the  inside  of  the  case  only  on  the  high  side,  and  when  the 
ring-shaped  crimping  punch  came  down,  this  thick  secciun  was 
pinched,  and  a streak  of  hardness,  and  consequently,  of  brittleness 
also,  extended  down  this  side  of  the  case,  and  it  was  at  this  place  that 
the  splits  appeared. 

In  the  cartridge  making  business,  there  is  never  a dull  moment! 

As  stated  above,  longitudinal  splits  in  the  body  of  a cartridge  case 
are  dangerous,  because  they  allow  gas  to  come  to  the  rear  through  the 
mechanism,  and  there  is  danger  of  injury  to  the  firer,  especially  to 
the  eyes.  One  thing  chat  encourages  such  splits  is  a chamber  which 
is  very  loose  fitting  at  the  rear. 

It  so  happens  that  the  Model  99  (1939)  7.7mm  Japanese  rifle  has  a 
bore  only  a little  bit  larger  than  ours;  three  thousandths,  to  be  exact, 
as  this  rifle  is  a .303.  The  cartridge  is  a few  thousandths  larger  than 
ours  is  at  the  rear  end,  and  is  shorter  than  ours.  Therefore  it  is  quite 


2 10 


Ha'icher’s  Notebook 


easy  co  convert  these  Japanese  rifles  to  shoot  our  ammunition  by 
deepening  the  chamber;  or  oar  .30  caliber  cartridges  can  be  necked 
down  to  work  in  these  guns.  Unfortunately*  however,  the  rear  of 
the  chamber  is  too  big,  and  every  time  a U.  S.  ,^o-’o6  cartridge  is 
fired  in  one  of  these  guns,  there  is  a strain  on  the  rear  of  the  car- 
tridge case,  inviting  it  to  split.  If  the  brass  is  perfect  with  no  flaws  or 


30-  06  IN  RECHAMBERED  7 7MM 


SAME  AFTER  FIRING 


GAS  LEAKS  IN  CASE 

Top:  .30-*06  tsnrldge  io  r«cbainber«<l  Japanese  7.7miu.  Note  the  clcafaace 
Around  the  rear  of  the  cartridge  ca5e,  which  for  reasons  of  clarity  ia  slightly 
exaggerated  in  the  sketch. 

J^ddie:  .30«’0d  cartridge  case  in  rechambered  7-7mm  Rifle  after  firing.  Note 
that  the  thin  walls  of  the  case  htnc  expanded  to  fit  the  chamber,  but  the  bead  of 
die  case,  where  the  metal  is  (hick,  has  not  exp^ed. 

Douom:  When  this  .30-‘0<>  cartridge  was  fired  in  a Japanese  rifle,  two  longi- 
tudinal splits  developed  in  the  case  as  shown,  pecmitliag  hoi  gas  at  high  pressure 
to  escape  violently  to  the  rear.  The  case,  seiu  in  by  the  member  to  whom  the  ac- 
cident happened,  is  head  stamped  F.A.  39.  Fortunately  no  serious  injuiy  rcsulicsi. 

planes  of  weakness,  there  is  slight  chance  of  having  this  happen, 
but  if  the  weakness  is  thcre^  such  a split  will  happen  more  easily  than 
it  will  in  the  tighter  chamber  of  the  M 1903  rifle;  and  more  gas  will 
come  back,  as  the  loose  chamber  gives  more  room  for  Ji.  Su  far, 
(March,  1947),  I have  seen  only  one  case  where  this  happened  with 
the  Model  99  (1939)  7.7  rifle  chambered  for  onr  cartridge,  but  1 
expect  to  see  more. 

These  Jap  rifles  are  good  strong  rifles,  but  they  are  by  no  means 


The  Strencih  of  Military  Rifles 


211 


proof  againsc  blowing  up  if  abused.  Recently  some  boys  cried  shoot* 
ing  .35  Remington  cartridges  in  one  of  these  guns.  The  bolt  closed 
so  hard  that  the  boys  used  a mallet  to  get  it  shut,  and  tliey  actually 
fired  two  shots  with  no  damage  to  the  gun;  but  on  the  third  shot 
the  receiver  gave  way  completely  and  the  firer  had  a piece  of  steel 
embedded  in  his  brain.  I am  happy  to  be  able  to  state,  however,  that 
after  a delicate  operation,  the  life  of  this  intrepid  young  cKperinieotcr 
was  saved. 


Receiver  Steels  and  Heat  Treatment 

The  trouble  with  weak  receivers  that  occurred  in  1917,  and  which 
has  already  been  mentioned  briefly,  led  to  1 complete  change  in  the 
heat  Treating  rnethotk  ar  Springfield  Armory,  and  to  change  of  heat 
treatmuu  and  afrerwanl,  n change  of  steel  at  Kock  island.  Both  these 
important  changes  were  later  followed  bv  i^rhcrs.  In  order  to  under- 
stand just  what  happened  and  the  reasons  for  w hat  occurred,  it  is 
necessary  to  go  back  into  history  a bit. 

From  the  time  the  Springfield  Rifle  went  into  production  in  *903, 
and  up  until  1927,  the  receiver  and  bolt  were  made  of  Springfield 
Armory  Class  C StecL,  afterward  W.  1325,  having  a composition 


as  follows: 

Min.  Max< 

Carbon  .20%  .30% 

Manganese  1.10%  1.30% 

Silicon  *15%  •}$% 

Sulphur  .05% 

Phosphorus  .05% 


The  receiver  was  forged  under  a 2,000  pound  drop  hammer,  hot 
trimmed,  and  then  while  hot  was  given  one  blow  in  tne  forging  dies 
under  the  hammer  10  straighten  it.  It  was  next  put  in  charcoal  and 
allowed  to  cool  very  slowly.  It  was  then  pickled  to  remove  the  scale, 
and  again  put  under  the  drop  hammer  cold  to  bring  it  to  size,  after 
which  it  went  to  the  receiver  shop  where  all  machine  operations  were 
performed. 

After  machining  was  finished,  the  receivers  were  heated  in  bone, 
four  in  a pot,  co  1500®  F.  and  kept  at  this  temperature  four  hours. 
This  was  in  a muffle  type  oil  furnace.  The  receivers  were  then 
quenched  in  oil. 

At  Rock  Island  receivers  were  made  from  the  same  steel  until 
1918.  The  treatment  was  as  follows: 

Pack  in  charred  leather  in  pots.  Heat  to  1475  to  1500^  F.  and  hold 
at  rhis  temperature  for  3^  to  4 hours.  Quench  in  oil. 

This  quenching  from  a high  temperature  made  the  receiver  fairly 
hard  all  the  way  through,  though  the  surface  and  the  material  near 
the  surface  into  which  the  carbon  from  the  charred  leather  had 
penetrated  were  harder  chan  the  interior,  so  that  the  piece  was 
actually  case-hardened. 

Now  the  harder  the  steel,  the  greater  its  tensile  strength,  and  these 
receivers,  being  quite  hard,  were  very  strong  and  highly  resistant  to 


212 


Receiver  SteeLvS  and  Heat  Treatmekt  213 

a sl(nvly  applied  load.  Also,  the  harder  the  steel,  the  more  brittle 
it  is  when  subjected  to  a sudden  shock. 

The  verv  hard  surface  had  excellent  wearing  qualities,  and  made 
a fine  smooth  working  action.  When  proper Iv  hcadspaced  and  used 
with  aiiiinunition  of  good  qualit\%  rlicsc  receivers  ga\e  excellent  re- 


Sphn afield  rifle  whh  low  numbered  receiver,  biirsr  «ii  Simlv  lUmk.  K.  Ocio* 
her  24,  J92T,  by  having  a 7.9  German  sc^^ice  can  ridge  lired  in  ii.  Suth  a lanriduc 
dred  in  a Springflold  rifle  result  in  a prcv5urc  of  over  75,OOo  ll>s.  per  >qujrc  inch. 
Ic  may  bufst  a low-nurabeicd  receiver,  bui  le^c^  have  shown  ihai  jhe  double  heat 
treated  receivers  will  stand  this  mis>iccaimem  without  giving  wa).  Fur  full  report 
see  Chapter  p.  4$8. 

suits.  The  Springfield  rifle  had  then  been  in  use  for  some  fourteen 
years,  and  there  were  about  700,000  of  them  in  existence,  and  there 
had  never  been  any  complaint,  though  it  was  later  found  that  so)iic 
of  them,  while  showing  a high  static  .strength,  won  id  shorter  under 
a sudden  blow. 

The  maxi  muni  working  pressure  for  the  service  cartridge  was 
50,000  pounds  per  square  inch.  Each  finished  rifle  was  proof  fired 
with  a test  cartridge  or  blue  pill  giving  a 40 'i,  overload,  or  70,000 
pounds  per  square  inch,  after  which  it  was  function  fired  with  five 
service  cartridges.  This  eliminated  most  of  the  weak  ones.  Very  rarclv 
one  would  break  in  service,  but  usually  thib  could  be  traced  to  some 
abuse,  and  anyway,  ic  happened  so  seidom  that  it  caused  no  comment. 


214 


IIaichrr’s  NarEBOOK 


Whea  Wurld  War  L cainc  along,  the  production  of  rifles  was 
stepped  up  CO  the  maKimuni  possible,  both  at  Springfleki  and  at  Rock 
Island,  and  at  the  same  time  several  new  companies  tried  then*  hand 
ac  making  ammunition,  and  some  of  the  ucw  cartridges  were  far 
from  satisfactory  in  f|iialiry. 

This  was  tlie  situation  when,  as  already  described,  I was  given  the 
job,  in  the  spring  of  1917,  of  investigating  the  cause  of  the  damigc 
to  two  rifles  sent  in  from  the  new'  cartridge  factory  of  the  Naiional 
Brass  and  Copper  Tube  Co.,  at  Hascings-on-lludson.  In  both  of  thc>c 
rifles  the  receivers  has  been  demolished,  but  the  barrel?  were  intact, 
with  the  cases,  or  what  remained  of  them,  still  In  the  chambers. 

This  was  only  a year  after  my  graduation  fi*oni  ihc  Ordnance 
School  of  Technology  at  Warertow^n  Arsenal,  where  I had  taken, 
among  other  subjects,  a course  on  the  mccalUirgy  of  iron  and  steel 
vmder  Dr.  Fay  of  Massachusetts  Institute  of  Technology,  I was  bv 
no  means  a skilled  mccalliiigisc,  but  at  least  I thought  I knew  burnt 
steel  when  1 saw  it  and  this  is  what  the  fractured  surface  of  the 
first  rifle  looked  like  to  me. 

The  gnn  had  been  fired  only  252  rounds  when  it  gave  wav.  The 
engineers  who  examined  the  rifle  at  the  carrriilgc  factors*  where  it 
failed  sent  along  a note  which  suicd:  ^‘Ic  is  the  judgmeiu  of  everv- 
one  who  has  seen  the  broken  edges  of  the  receiver  that  ihc  steel 
most  emphatically  is  not  properly  case-hardened  as  [Kr  specifications, 
and  that  it  ho.s  been  heated  too  liot  before  <]uenching,  creating  crys- 
tallization and  resulting  in  the  greatest  weakness.  There  is  no  wonder 
it  burse.” 

1 could  quite  agree  that  the  seed  appeared  to  have  been  weakened 
by  overhearing.  Pieces  of  this  receiver  placed  in  a vise  and  tapped 
with  a hammer  simply  fell  apart. 

On  these  two  guns  there  was  also  evidence  that  the  heads  of  the 
cartridge  cases  had  been  soft,  and  liad  ex jw tided  licfore  t.hc  receiver 
failure,  thus  leccing  gas  under  high  pressure  gee  out  into  the  receiver 
ring  w'here  it  had  such  a laige  surface  to  work  on  chat  the  load  011 
the  receivers  was  greatly  increased. 

My  experiments  resulted  in  a report  which  stated  in  effect  that 
the  damage  had  been  caused  by  a combination  of  soft  headed  car- 
tridge eases  and  receivers  which  were  weak  and  brittle;  and  further, 
thai*  similar  weak  and  brittle  receivers  were  still  coming  off  the  pro- 
duction line.  Half  a dozen  new  receivers  were  taken  at  random  from 
the  assembly  room  and  fastened  in  a vise  and  struck  with  a hammer. 
Several  of  them  shartcred  to  pieces. 

As  has  been  stated  above,  this  report  led  to  the  cmplovnient  by 
the  Armor)'  of  the  best  obtainable  metallurgical  staff,  headed  by 
Maj.  W,  H.  Beilis,  a well  known  specialist  on  the  heat  treatment  of 
iron  and  steel. 

One  fact  that  this  staff  quickly  developed  uas  that  the  forging 


Receiver  Steels  and  Heat  Treatment  215 

temperature  was  not  being  suiHcieatLy  controlled.  Too  much  reliance 
was  being  placed  on  the  knowledge  and  experience  of  the  furnace 
men  who  heated  the  rcceiTer  and  bole  steel  in  the  forge  shop. 

These  men  thought  that  they  could  tell  when  a piece  had  the  right 
heat  just  by  looking  into  the  furnace.  They  were  proud  of  their  ex- 
perience, ssfcill,  and  ability,  and  believed  that  if  cook  years  of  practice 
to  become  expert  in  judging  the  forging  temperature.  They  were 
highly  paid  craftsmen,  who  were  jealous  of  their  exclusive  skill,  and 
who  both  hated  and  feared  these  new'  f angled  pyrometers  w'hich 
threatened  to  make  useless  their  special  knowledge. 

The  first  step  taken  by  the  metallurgists  was  to  install  pyrometers, 
when  it  was  quickly  found  that  the  “right  heat’'  as  judged  by  the 
skillful  eye  of  the  old  liiTJers  was  up  to  joo  degrees  hotter  on  a 
bright  sunny  day  chan  it  was  on  a dark  cloudy  one.  This  variation 
was  of  course  made  much  worse  by  the  fact  that  production  had 
been  stepped  up  to  such  a degree  that  many  less  skillful  men  had  to 
be  employed  on  this  and  all  other  critical  jobs.  The  production  rush 
had,  as  always  happened,  caused  a drop  in  the  quality  of  3 product 
which  even  at  best  was  not  up  to  what  could  he  obtained  by  the  most 
modern  controlled  methods. 

A further  result  of  die  fine  work  on  die  lucfallurgkal  improvement 
of  the  boh  and  receiver  by  .Major  Beilis  and  also  by  Lieut.  Col. 
W.  P.  Barba,  Chairman  of  the  Ordnance  Department  Board  on  Sreel, 
and  others,  was  the  development  of  an  entirely  new  so-callcd  double 
heat  treatment  for  the  Springfield  Armory  Class  C Steel,  as  foiiowsi 

The  receiver  was  forged  under  a 2000  pound  drop  hammer,  hot 
trimmed,  and  then  given  one  blow  under  the  hammer  to  straighten  it, 
after  which  it  was  allowed  to  cool  in  an  open  pan.  It  was  then  pickled 
to  remove  scale,  cold  trimmed,  and  bronghc  to  siVe  cold,  tinder  the 
drop  hammer.  It  was  clicn  annealed  by  packing  in  charcoal,  hearing 
to  1500  degrees  F.  for  2 hours,  and  cooling  in  the  furnace,  after 
which  ir  was  pickled,  inspected,  and  machined. 

After  machining,  the  receiver  w'as  heated  in  bone  in  an  American 
Gas  Company  Carburizing  Furnace  at  1500  degrees  F.  for  zVi  hours, 
then  quenched  in  oil.  It  was  re-heated  to  1300  degrees  F.  in  a salt  bach 
for  5 minutes,  and  again  quenched  in  oil.  It  was  next  drawn  at  350 
degrees  F.  in  an  oil  bach  and  air  cooled,  and  tested  for  hardness  with 
a bcleroscope,  which  should  give  a reading  between  45  and  60.  rhis 
would  correspond  roughly  to  from  33  to  44  Rockwell  C. 

The  difference  in  the  resulting  receiver  (and  bolt)  s true  cure  be- 
tween the  old  and  the  new  creatiricnt  can  be  outlined  briefly  as  fol- 
lows: 

In  both  methods,  the  receivers  (and  bolts)  were  carburized  so  that 
the  metal  on  and  near  the  surface  had  a higher  carbon  concent  chan 
did  the  inside.  In  the  old  method  the  receiver  was  simply  heated  above 
the  hardening  temperature  of  the  steel  and  then  quenched.  This  made 


Hatcher’s  Notkbckjk 


2(6 

the  receiver  hard  all  ihc  way  through,  though  the  carburized  surface, 
hjvmg  a higlier  carbon  comen c came  out  harder  cl) an  the  lower  car- 
bon interior,  which,  however,  was  still  hard  enough  to  be  brittle 
under  shock. 


Compariviii  oJ  cav;  hanJuicd  rtwivers  as  tmdc  ar  Sj)fin^Ja*]d  ami  Hoik  Island 
up  (a  iyi8,  with  chc  double  Kcai  treated  fci elvers  made  a(  Sprin afield  he i ween 
n>18  and  1^27. 

lop  lefn  Receiver  No.  201,812,  Top  fifihi:  Keieiver  No.  ^18,921,  Middle  Icit : 
Receiver  No.  319^70.  These  were  all  of  ihe  oW  case  hardened  type  A li|:h(  blow 
with  a jtcvl  rod  shattered  the  side  rib  of  the  recei\er,  showing  that  the  steel,  while 
strong,  was  too  bard  to  resist  impact. 

Middle  right:  Receiver  No.  HtW.MV.  Bottom  left:  Receiver  No.  811,951.  Bottom 
fight:  Receiver  No.  833,698.  These  receivers,  numbered  above  800,000,  all  had 
the  double  heat  ucaimuii,  giving  ii  hard  surface  and  a sc»fi  tenacious  core.  When 
repeated  blows  with  a steel  rod  failed  fi>  shatter  the  side  rib,  whicli  Is  the  weakest 
pwt  of  the  receiver,  they  were  fastened  in  a heavy  vise  and  belabored  unmercifully 
with  a heavy  iron  bar.  Note  that  while  cracks  appeared  in  the  hard  surface  where 
:i  was  bent,  the  soft  mterinr  held  the  metal  together.  These  dotible  heat  treated 
receivers  fitted  with  bolts  having  the  same  trcainient  produced  the  strongest  rifle 
actions  ever  made. 


The  new  treatment  was  based  on  the  fact  that  the  higher  the  carbon 
content  of  the  steel,  the  lower  the  temperature  to  which  it  muse  be 
heated  to  make  it  harden  when  ijiienchcd  from  this  temperature. 

As  the  reader  is  no  doubt  aware,  the  hardness  of  carbon  sreel  is 
largely  dependent  on  the  form  in  \vhicli  the  carbon  exists  in  the  sieel. 
If  the  carbon  is  in  a form  called  Pearlire,  the  steel  will  be  soft.  If  it 
is  in  a form  called  .Martensite,  the  steel  will  be  hard,  If  it  is  part  one 
and  part  the  other,  the  hardness  will  be  intermediate.  When  steel  is 


Receiver  Stfet^  aki>  Hrat  Trfatvirnt 


217 

heated,  a point  is  reached  at  which  it  seems  to  absorb  heat.  At  this 
so -called  decalcscence  point,  the  Pcarlice  turns  into  Martensite.  This 
is  one  of  the  “critical”  points  of  steel.  If  the  steel  is  heated  to  this 
point  and  then  cooled  slowly,  another  critical  poini,  called  the  rc- 
calescence  point,  is  reached  some  200  to  250  degrees  lower,  where  rhe 
steel  stops  cooling  for  a time  and  actually  seems  to  give  out  heat  as 
the  Martensite  turns  back  to  Pearlite.  Steel  cooled  slowly  in  this  way 
will  come  out  soft.  But  if,  %vhen  the  steel  has  readied  the  first  critical 
point,  it  is  cooled  suddenly,  as  by  quenching  in  brine  or  oil,  the 
Martensite  is  trapped  before  it  can  change  back  and  the  metal  be- 
comes very  hard,  This  operation  is  called  hardening. 

If  the  hardened  steel  is  then  heated,  it  begins  to  soften.  If  heated 
a little,  it  is  softened  slightly.  If  heated  nearly  to  the  critical  point, 
it  becomes  very  soft. 

Now  the  newer  double  heat  treatment  takes  advantage  of  rhe  fact 
chat,  as  noted  above,  the  higher  the  carbon  content  of  the  metal, 
the  lower  the  temperature  to  which  it  must  he  brought  to  make  it 
harden  when  cooled  suddenly. 

Thus  if  the  piece  is  quenched  from  a temperature  jast  high  enough 
CO  permit  hardening  the  carburized  outside  surface,  the  lower  carbon 
inside  core  will  remain  very  soft. 

In  the  revised  heat  treatment,  hearing  to  1500  degrees  and  quench- 
ing hardens  the  receiver  through  and  through,  and  refines  the  grain. 
Re-headng  co  1300  degrees  draws  the  temper  and  softens  the  nictal. 
This  temperature  is  above  the  hardening  point  of  the  high  carbon 
outside  surface  but  not  hoc  enough  to  cause  che  low  carbon  inside 
core  to  harden  when  quenched.  When  the  piece  at  1300  degrees  is 
then  plunged  into  oil,  the  outside  surface  becomes  very  hard,  and 
the  inside  core  remains  soft  and  cough.  Afterwards  the  receivers  are 
heated  to  350“  F.,  which  slightly  reduces  the  hardness  of  the  surface 
I aver  and  adds  to  its  toughness. 

Typical  of  che  old  single  heat  treatment  is  the  following  test  of 
three  receivers: 

After  firing  ten  rounds  of  70,000  pounds  per  square  inch  the  in- 
crease in  head.space  was  found  to  be  from  .00%  inch  to  .ooO  inch. 
One  of  the  three  receivers  tested  was  blowm  up  with  one  round  of 
80,000  pounds  per  square  inch  and  the  other  two  receivers  broke 
with  che  firing  of  one  round  each  of  100,000  pounds  per  square  inch. 

On  the  other  hand,  receivers  with  the  double  heat  treatment  could 
not  be  broken  with  the  highest  proof  loads  that  could  be  made  up 
for  this  caliber,  namely  125,000  pounds  per  square  inch. 

In  1926  a Board  investigating  this  subject  cook  from  stock  24 
rifles  made  in  1918  having  double  heat  created  receivers  and  tested 
them  with  results  as  given  below: 


TTiis  double  beai  treated  rtteivrr  and  bolt  withMood  a destruction  charge  of 
45  grains  ol  biillseye  behind  a 170  grain  flat  based  proof  bullet,  giving  a pressure 
of  around  133,000  pounds  per  square  inch.  The  head  of  the  case  practically 
melted  away,  leuiiig  the  gas  tnji  into  the  receiver  well,  where  it  messed  things 
up  a bit,  and  blew  splinters  off  the  stockj  but  cbe  action  held  hrm. 


Receiver  Stefxs  avo  HtA*r  Treat  mext 


219 


HEADSPACE 


Receiver  No. 

At  Suit 

After  10 
70000  # sq.  in. 

proof  shots 

After  1 
Soooo  # sq.  in. 
proof  shot 

After  j 

125000  # sq.in. 
proof  shot 

853-J98 

1.945 

1,946 

4 « 1 « 

O.K. 

853.J47 

1.942 

* * * « 

O.K. 

859.»'3 

1.942 

'W 

O.K, 

856.789 

1.942 

* * * * 

O.K. 

857.661 

1.942 

1.944 

O.K. 

858.771 

T.941 

1.942 

« « « * 

O.K. 

859.576 

1.941 

1-945 

O.K. 

855485 

r.941 

‘•944 

O.K. 

859.797 

1.942 

‘•944 

>-944 

O.K, 

860,825 

r.946 

1,948 

i/fSO 

O.K, 

860,995 

1.942 

»-944 

‘•944 

O.K. 

861,038 

1.944 

1.946 

1.946 

O.K. 

862,031 

1.941 

‘•94* 

‘•945 

O.K. 

861*534 

i-944 

‘945 

O.K. 

861,747 

1.94* 

‘•945 

*•945 

O.K. 

862,564 

r.941 

1.942 

>•94* 

O.K. 

860,651 

;.942 

>•945 

>•945 

O.K. 

861,049 

t*94T 

>947 

1,948 

O.K. 

863,9^ 

r.940 

1.940 

1.940 

O.K. 

865,717 

'•943 

‘•94^ 

1.946 

O.K. 

866,906 

1.940 

1.941 

'•94* 

O.K. 

87^513 

t.944 

*•950 

‘•95* 

O.K. 

868,526 

1.940 

1.941 

1.941 

O.K. 

868,622 

1.941 

>944 

>•944 

O.K. 

Receivers  made  at  Rock  Island  Arsenal  as  well  as  at  Springfield 
Armory  had  been  involved  in  the  accidents  occurring  in  1917  and 
1918  which  caused  the  revision  of  heat  treatment.  Rock  Island  was 
using  the  same  steel  that  Springfield  wcificd,  and  they  made  some 
experiments  that  verified  the  Springfield  results.  According v nn 
May  ir,  1918,  beginning  with  receiver  No.  285*507  they  adopted  an 
improved  heat  treatmenr*  as  described  later  «n  for  the  carbon  man- 
ganese steel  receivers  and  bolts.  In  addition*  on  August  1*  1918,  bur 
receiver  No,  319.911,  they  adopted  a nickel  j^tecl  similar  to  that  being 
used  at  the  time  for  the  1917  rifles  under  manufacture  bv  Winchester, 
Remington  and  Eddy  stone. 

This  *35%  carbon,  3.5%  nickel  steel  was  given  the  following  treat- 
ment: 

Heat  in  sale  bath  to  1500®  F.*  quench  in  oil*  and  draw  in  sodium 
nitrate  at  600®  V.  for  30  m mutes.  Then  test  for  hardness  with  Scler- 
scopc  which  must  be  betwe^  55  and  70  (this  corresponds  roughly 
to  41- J2  Rockwell  C.). 

Tests  made  an  these  Rock  Island  nickel  steel  receivers  gave  the 
following  results: 


120 


Hatch  kr’s  Notebook 


Treatment; 


Head  Space 
Nickel  Steel 

it  M 

it  a 

u a 


Oil  quenched  from  i6oo* 

After  10 
70000  Ibs.sq.  in. 

F.  Reheated  co 
After  i 

80000  llis.sq.  in. 

Ac  Scare 

proof  shots 

proof  shoe 

1.941 

*•944 

1.949 

1,941 

1,94a 

<•95* 

1,941 

1,948 

Bole  jammed 

1940 

14241 

Bole  jammed 
Bole  jammed 

1.940 

14146 

700*  F- 
After  I 

1 25000  ll)S.  SC],  in, 
proof  shot 
O.K. 

O.K. 


Treatment: 

I 

Head  Space 
Nickel  Steel 

<i  M 

I U it 

I 


Oil  quenched  from  1500* 

After  10 
70000  ll>s.  sty  ill. 
At  Stare  proof  shots 
1,941  1,945 

1.940  1,945 

1.941  1,945 


F.  Reheated  to 
After  I 

80000  Ibs.sq.  in. 
proof  shot 


F. 

After  1 

litfKXj  lbs.  sq.  in. 
proof  shot 
O.K. 

Blew  up 
Blew  up 


Troatment: 


Head  Space 
Nickel  Steel 

u u 

u a 


Oil  quenched  fnmi  1425* 

After  10 
70000  lbs.  sq.  in. 
At  Start  proof  shorn 


F.  Reheated  to  650*  F. 

After  I After  i 

Koooo  Ibs.sq.  in.  125000  Ihs.  scj.  iu. 
proof  shot  proof  shot 
Broke 

Blew  up 
Blew  up 


Some  time  after  World  War  I the  question  arose  as  to  just  how 
receivers  with  the  old  heat  treatment  could  be  identified.  Sprinjif field 
stated:  'The  exact  date  of  the  change  from  the  old  to  the  new 
method  is  not  known.  Between  receivers  number  750,000  and  780,000 
there  seems  to  have  been  a shifting  in  heat  treatment.  Receivers  No. 
800,000  was  completed  on  February  20,  19 and  it  is  known  that 
all  receivers  after  800,000  received  the  double  heat  treatment.” 

While  for  practical  purposes  the  division  between  the  old  and 
the  new  heat  treacment  at  Springfield  Armorv  may  be  taken  as  re- 
ceiver niimher  800,000,  this  cannot  be  considered  completely  acxiiratc, 
as  it  has  been  said  that  a few  receivers  of  the  old  treatment,  which 
had  been  set  aside  for  some  reason  were  put  back  in  the  assembly  line 
just  after  number  800,000,  It  is  significant  that  out  of  the  68  acci- 
dents reported  between  1917  and  1929  in  which  receivers  of  the  M 
1905  rifle  were  shattered  or  fractured  only  one  was  supposed  to  be 
of  the  new  Springfield  double  heat  treatment,  and  that  one,  which 
occurred  in  1929,  involved  receiver  number  801,548.  T have  no  doubt 
chat  this  was  actually  a receiver  having  the  old  heat  treatment. 

As  to  Rock  Island  receivers,  on  September  24,  1926,  Rock  Island 
replied  as  follows:  “There  arc  no  records  to  show  the  serial  number 
at  which  a change  was  made  from  carbon  to  nickel  steel.  Miscel- 
laneous shop  memoranda  indicate  that  this  change  occurred  shortly 
after  August  i,  1918.  Tlie  serial  numbers  in  August,  1918,  run  up- 
ward from  319,921.  One  fact  seems  clear  and  that  is  that  all  finished 


Rrcf.ivf.r  Stfei.s  AM)  Heat  TRE  vrMrM 


22  1 


receivers  of  nickel  steel  were  stamped  ‘XS*  on  the  face  at  the  front 
end.  This  scamping  is  covered  by  the  assembly  of  the  barrel  but  can 
be  seen  on  disassembled  receivers.  A fairly  sure  test  can  be  made  with 
a file  as  all  nickel  seed  receivers  cut  easily,  while  filing  makes  no  im- 
pression on  the  file- hard  carbon  receivers.’ ' 

On  September  27,  1926,  the  following  snppicmcnral  in  forma  don 
was  furnished  by  Rock  Island  Arsenal:  “Stock  iiioveincnt  records 
have  been  found  showing  both  carbon  and  nickd  steid  receivers  heinof 
made  each  month  to  hichide  Decetfiber  and  July  No 

separation  of  serial  numbers  was  made. 

‘in  February,  1918,  the  heat  treatment  of  carbon  steel  receivers 
was  changed  to  the  foUowing: 

“Annealed  at  1500’'  F.  for  2 hours,  dropped  to  1050*  in  the  furnace, 
then  removed  and  air  cooled.  Hardened  by  heating  to  1550  to  1600'’ 
F.  for  15  minutes  and  quenched  in  Houghton’s  X^o.  2 quenching  oil. 
Rdwated  to  1425*  F.  followed  by  quenching  in  oil.  Washed  in  soda 
kettle,  Drawn  in  oil  at  500'’  F. 

“Instructions  were  issued  on  March  2,  1918,  to  destroy  all  carbon 
steel  receivers  havhi^  the  old  beat  treatment  remaining  on  hand  and 
CO  assemble  only  receivers  having  the  new  heat  treatment  after  that 
dace.  Some  16,000  receivers  were  destroyed. 

“The  serial  numbers  of  receivers  manufactured  at  Rock  Island 
Arsenal  prior  to  February  1918,  run  from  No.  1 to  No.  285,506. 
(Manufacture  w'as  suspended  on  Januarv  50,  1918,  and  none  were 
made  during  February.  March  or  April.  On  May  r9i8,  maiiu- 
facturc  0/  receivers  was  resumed  with  serial  number  285,507. 

“It  would  seem  that  if  it  were  necessary  to  replace  those  of  Spring- 
field  Armory  manufacture  hearing  serial  numlKrs  below  800,000  it 
it  would  be  dc??irahlc  to  do  the  same  thing  with  those  of  Rock  Island 
Arsenal  manufacture  of  serial  numbers  less  than  285,507  as  the  heat 
treatment  was  the  same  at  bocli  arsenals.” 

After  World  War  I was  over  and  the  Army  w'as  dcmuhiliy.ed,  the 
War  Department  began  to  consider  the  question  of  what,  if  anything, 
should  be  done  about  the  low  numbered  receivers  in  service. 

On  December  2,  1927,  a Board,  consisting  of  Major  Herbert 
O’Leary,  Major  James  Kirk,  Captain  James  L.  Hatcher  and  ist 
Lieutenant  Rene  R.  Studler,  was  convened  to  recommend  the  policy 
to  be  adopted  governing  the  use  of  Model  1903,  caliber  .30,  rifle 
receivers  of  Spnngficld  Armor)-  manufacture  bearing  serial  numbers 
below  800,000  and  Rock  Island  receivers  below  285. 5^07. 

The  following  extracts  from  the  proceediagb  of  the  Board  are  of 
interest: 

A statement  by  Frank  ford  Arsenal,  June  25,  1925;  “In  view  of  the 
large  number  of  accidents  occurring  with  rifles  having  serial  numbers 
below  800,000,  this  Arsenal  considers  that  ail  such  rifles  should  be 
withdrawn  from  service  and  not  used  for  any  firing.” 


222 


Hatcui£r’s  Notebook 


And  a staccinent  from  Frankford  Arsoial  on  April  1926:  “This 
Arsenal  thinks  char  not  only  the  firing  of  grenades  in  rifles  manu- 
factured at  Springfield  Armory  with  receiver  serial  numbers  below 
8oo»ooo  should  be  prohibiced,  buc  that  the  firing  of  all  small  arms 
ammunition  in  such  rifles  should  be  prohibiced,  and  this  opinion  has 
been  expressed  by  this  Arsenal  upon  se\'eral  occasions. “ 

Springfield  Armory  on  June  25,  1926,  stated,  referring  to  the  above: 
“Tins  x\rmory  agrees.  Receivers  manufactured  ac  Springfield  Armory 
with  receivers  below  800,000  arc  known  to  be  weak.  The  use  of  a 
rifle  with  such  a receiver  is  dangerous  if  the  pressures  are  above 
normal  or  chc  headspace  is  excessive.” 

[n  1923  Springfield  Arnniry  undertook  an  investigation  to  determine 
the  practicability  of  re- heat  treating  receivers  with  numbers  below 
800,000  to  determine  if  they  could  thus  be  given  strength  equal  to 
receivers  of  later  manufacture.  One  hundred  receivers  were  re-heat 
created  and  tested.  The  result  indicated  a considerable  variation  in 
carbon  concent,  many  receivers  being  low  enough  to  require  rc- 
carburizing  before  heat  treating. 

The  test  »;howcd  that  while  the  old  receivers  were  improved  by 
rc-hcat  ircafing,  they  were  still  likely  to  burst  at  pressures  slightly 
in  excess  of  50  perceni  above  normal,  while  the  later  double  heat 
treated  receivers  would  successfully  withstand  very  high  pressures* 

The  Board  stated:  “The  test  brings  out  quire  clearly  the  fact  that  uni- 
form results  cannot  be  obtained  by  re^hear  treating  old  receivers 
which  vary  widely  in  chemical  cornposition.” 

It  may  be  noted  that  one  trouble  encountered  with  the  low  num- 
bered receivers  was  that  some  of  them  were  dangerously  weak  bv 
reason  of  having  been  overheated,  or  burnt,  during  the  forging  proc- 
ess. No  antount  of  re-hcat  treating  ‘ivotdd  cure  this  trouble, 

Fn  one  of  the  experiments  at  Springfield  Armor\%  48  receivers 
were  carefully  re-heat  treated,  after  which  16,  or  one-third,  failed  on  1 
high  pressure  test.  ! 

The  Board  found:  ! 

( t ) That  low  numbered  receivers  are  not  suitable  for  service  use 
in  their  present  condition. 

(2)  That  means  have  not  yet  been  determined  for  making  such  ! 
receivers  suitable  for  service  use. 

(3)  'Ihat  it  is  considered  impracticable,  if  not  impossible,  to  re-  ^ 

heat  treat  these  receiver?  in  such  a manner  as  to  make  them  | 
serviceable.  J 

The  Board  recorninciidcd  iliat  tlie  receivers  be  withdrawn  from  | 
service  and  scrapped.  I 

After  considering  the  proceedings  of  the  Board,  the  Chief  of  ; 
Field  Service,  Brigadier  General  Samuel  Hof,  on  February  7,  1928,  1 

made  the  following  recommendation  to  the  Chief  of  Ordnance,  w'hich  * 
w'as  approved  as  a policy:  i 


Rf.C7.iver  Steels  ani>  Heat  Treatment  223 

“Our  ammunicion  is  getting  worse  and  accidents  may  be  somewhat 
more  frequent.  On  the  other  hand,  some  of  these  early  rifles  have 
liccn  in  use  for  many  years  and  undoubtedly  some  of  them  have  worn 
out  several  barrels.  I do  i>ot  think  the  occasion  merits  the  withdrawal 
of  the  rifles  of  low  nuinbci*s  in  the  hands  of  troops  until  the  rifle 
is  otherwise  unserviceable.  On  the  other  hand,  1 do  not  think  wc 
are  justified  in  issuing  such  rifles  from  our  establishment's.  I recom- 
mend that  we  instruct  our  Ordnance  establishments  10  no  longer 
issue  rifles  with  these  questionable  receivers,  that  sucii  rifles  be  set 
aside  and  considered  as  a war  reserve  and  the  question  of  the  iiltimiue 
replacement  of  the  receivers  be  deferred.  When  rifles  are  turned 
in  from  the  troops  for  repair  the  receivers  having  these  low  numbers 
should  be  scrapped.’" 

During  the  twelve  years  from  1917  to  1929  inclusive,  31  receivers 
of  Springfield  manufacture  arc  recorded  as  having  blown  up.  together 
with  aj  of  Rock  Island  manufacture  and  5 listed  as  unknown.  Of 
these,  one  Rock  Island  receiver.  No.  445,(36.  was  cicfinicely  of  new 
manufacture.  Of  the  Springfield  Armory  receiver,  No.  8oi.54fi,  which 
oddly  enough  is  the  last  one  on  the  list  in  19291  was  recorded  as 
having  the  new  heat  creamicnt.  This,  however,  is  doubtful  because 
as  above  stated,  it  is  known  that  just  about  No.  800,000  a small  lot 
of  old  receivers  \vhich  had  been  set  aside  for  some  reason  were  found 
and  pur  in  process,  and  the  number,  together  with  the  fact  that  no 
ocher  case  is  recorded  of  the  breakage  of  a receiver  of  double  heat 
treatment,  indicates  that  this  was  probably  one  of  this  special  lor. 
This  receiver  incidcnrally  was  burst  by  firing  it  with  a 7.gmm  Ger- 
man service  cartridge. 

Two  Springfield  receivers,  with  the  double  heat  rrearmenr,  Nos. 
946,508  and  951,718,  were  “deformed”  and  “bulged,”  rebpecrively. 
This  is  typical  of  the  double  heat  treated  receivers  when  excepcionallv 
high  pressures  arc  encountered.  They  will  always  hold  together,  even 
though  the  cartridge  head  may  open  up  and  allow  enough  gas  to 
escape  to  bulge  the  magazine  wall  and  splinter  the  .stock. 

In  this  latter  case  the  report  of  the  accident  stated:  “Damage  was 
caused  by  excessive  pressure  which  was  sufficiently  high  to  cause  the 
cartridge  case  to  fail  suddei^'  and  allow  gas  under  very  high  pressure 
to  escape  into  the  action.  Yhe  receiver  was  evidently  properly  hear 
treated  because  it  did  not  fractitre.^^ 

The  complete  tabulation  and  record  of  the  investigation  of  all 
accidents  to  the  U.  S.  Rifle  Caliber  .30,  Model  of  [903  which  were 
reported  between  the  years  of  1917  and  1929  inclusive  will  be  found 
in  the  last  chapter. 

Receivers  and  bolts  for  the  Springfield  rifle  continued  to  be  juade 
of  the  carbon  steel,  double  heat  treated,  until  April  i,  1927,  when 
a change  was  made  to  nickel  steel  with  rifle  No.  1,275.767. 

WTiile  Rock  Island  had,  as  noted  above,  been  using  nickel  steel 


224 


Hatcher's  Notebook 


for  part  of  chdr  producrion  since  Augiisr  1918.  Springfield  first 
approadied  a diaJigc  to  tills  material  ia  1926.  In  March  of  that  year, 
after  the  manufacture  of  rifles  had  been  discontinued  at  Rock  Island, 
25,doo  unfinished  nickel  steel  receivers,  together  with  a number  of 
other  unfinished  parts,  were  shipped  to  Springfield  Armory  to  be 
finished.  These  Rock  Island  receivers  were  f creed  of  steel  stated  to 
be  Hot  Rolled  Nickel  Steel,  S.  A.  specification  35-NS.  The  analysis 
furnished  at  that  time  was  as  follows: 


Carbon 

Manganese 

Phosphorus 

Sulphur 

Silicon 

Nickel 


.30%-  .40% 

.45%-  -50% 
.05%  or  less 
.05%  or  less 
.10%-  .25% 


Springfield  Armory  completed  the  manufacture  of  these  receivers, 
die  first  one  being  finished  about  April  r,  >927,  and  numbered  i,- 

275*7^7* 

In  August,  1926,  Colonel  SchuU,  Commanding  Ofiicer  of  Spring- 
field  Armory,  asked  the  Chief  of  Ordnance  to  approve  the  manu- 
facture of  an  experimental  lot  of  100  receivers,  bolts  and  cut-ofFs 
for  the  M 1903  rifle  to  be  made  of  nickel  steel,  WD  2340. 

In  his  letter,  ColuncI  Schull  stated  that  this  experimental  Int  of 
bolts,  receivers  and  cuc-olTs  would  be  used  in  a comparison  rest  with 
corresponding  parts  manufactured  of  the  plain  carbon  steel,  WD 
1325.  He  further  said,  '4t  is  believed  the  manufacture  of  rhis  number 
of  components  would  yield  valuable  experience  in  drop  forging  and 
heat  treating  and  develop  the  necessary  physical  qualities,  and  in 
addition  aid  in  determining  whether  or  not  machining  operations 
with  this  higher  grade  of  steel  will  be  materially  increased  using 
present  jigs,  fixtures  and  methods”  The  same  file  also  states,  ‘*At- 
tention  is  invited  to  numerous  complaints  which  have  been  made 
during  the  past  few  years  concerning  the  manner  in  which  bolts 
and  cut- offs  become  unserviceable.” 


Approximately  100  receivers  and  bolts  were  manufactured  from 
the  WD  2340  steel,  assembled  into  rifles  and  tested.  The  results  of 
the  tests  performed  were  studied  by  the  Ordnance  Office,  and  on 
March  6,  1928,  a letter  was  received  from  that  office  which  stated: 
“It  is  directed  that  a suitable  alloy  steel  be  substituted  for  carbon 
steel  heretofore  used  in  the  components  named.”  Chemical  composi- 
tion of  WD  2340  is  as  follows: 


Carbon 

Manganese 

Phosphorus 

Sulphur 

Nickel 


.35%-  45% 
.50%—  .80% 
.Max.  .o4S^^ 
Max.  .04% 

3.25%-3.7?% 


Rl^CtlVF.R  Stef.ls  and  Hrat  TrF-ATMKNT 


225 

It  will  he  noted  that  this  steel  differed  slightly  from  the  first  nickel 
steel  receivers  jnade  by  Rock  Island  Arsenal  and  Springfield  Armory 
between  1918  and  1927. 

Except  for  the  annual  assembly  of  National  .Match  rifles,  the  pro- 
duction of  the  1903  rifle  was  suspended  from  the  early  1930’s  until 
the  beginning  of  World  War  IT.  The  few  rifles  that  were  made  during 
this  period  had  receivers  and  bolts  made  of  nickel  steel  WD  2340. 

Likewise  the  WD  No.  8620  Steel  used  in  the  bolts  and  receivers  of 
the  Mi  Garand  rifle  and  the  M 1903  A3  and  A4  rifles  is  a nickcl- 
chroniium  molybdenum  steel  having  about  60  points  to  .70%) 

of  nickel  and  about  20  points  (.15%  to  25%)  of  carbon. 

Recapitulatmi 

For  ready  reference,  the  information  given  above  as  to  siecl 
compositions  and  heat  treatments  is  collected  together  here  along 
with  .some  other  material  not  already  given,  so  as  to  present  in  easily 
available  form  the  information  on  the  material  used  in  the  various 
military  rifles  used  in  the  Army  over  the  last  fifty  years. 

Krag  Jorgensen  Rifle.  (U.  S.  Rifle  Cal.  Model  of  /8p8) 

The  Barrel  was  made  of  Ordnance  Barrel  Steel  having  the  follow- 
ing composition: 


Carbon 

.45%  to 

•S5% 

Manganese 

1.00%  to 

I.JO% 

Sulphur 

Not  over 

.05% 

Phospliorus 

Not  over 

.05% 

The  Receiver  was  made  of  Springfield  Annory  Class  C Steel. 


Carbon 

.20%  to 

.JO% 

Manganese 

1.10%  to 

I.JO% 

Silicon 

.15%  to 

•35% 

Sulphur 

Not  over 

.05% 

Phosphorus 

Not  over 

.05% 

The  Bolt  appears  to  have  been  made  of  carbon  seed  having  around 
.5-5%  to  .6s;  % carbon  with  .45%  to  .55%  manganese. 

The  Springfield  Rifle,  Model  of  190^^  v:hh  Us  eherations  Aiy 

and  A4 

The  Barrel,  for  rifles  of  Springfield  Armory  make,  from  serial  No. 
I to  serkl  No.  1,532,878.  (This  includes  all  the  rifles  made  at  Spring- 


226 


Hatcher’s  Xotfbook 


field  Armory,  and  refers  to  the  original  barrel  only,  as  some  were 
rcbarrclled  in  the  course  of  repair  using  barrels  of  commercial  make.) 

Material:  Ordnance  Barrel  Steel  with  composition  as  given  above 
under  the  Krag, 

Treatment:  Quench  in  oil  at  i6oo®F.  and  temper  for  z hours  at 
1 200®  F. 


The  Barrel  fox  rifles  having  serial  mimbers  over  3,000,000,  made 
during  World  War  II. 

Materia!:  War  Department  (WD)  Steel  No.  1350  Special,  (resul- 
phurized),  Alternate,  WD  Steel  No.  1350  Modifled;  with  compositions 
as  given  below; 


WD  No.  1350  Special 


Carbon 

,45%  to 

•55% 

Manganese 

1.10%  CO 

1.35% 

Silicon 

.25%  CO 

•35% 

Resulphurized 

to 

.06% 

Phosphorus 

Not  over 

.06% 

WD  No.  1 350  Modified 

•45%  to  '55% 
1.10%  to  1.35% 
•25%  .35% 

Sulphur  Not  over  .05% 

Not  over  .06% 


Treatment:  Before  machining,  heat  to  a ccmpcranire  of  1525®  to 
1600®  F,;  oil  quench,  and  temper  to  Brincll  hardness  of  229  to  285. 
Stress  relieve  not  less  than  900®  F.  after  straightening  if  necessary. 


Receivers  and  Bolts  of  Springfield  Arnioiy  make,  from  serial  No. 
I to  serial  No.  800,000. 

Material:  Springfield  Armory  Class  C Steel  as  given  under  Krag. 
Treatment:  Carburize  in  bone,  4 in  a pot  at  ijoo®  F,  for  4 hours 
in  a muddle  type  furnace,  then  quench  in  oil 


Springfield  Receivers  and  Bolts  from  serial  No.  800,000  to  1,275,767. 

Material:  Springfield  Armory  Clasi>  C Steel  as  given  under  Krag. 

Treatment:  Heat  in  bone  in  an  American  Gas  Company  Carburizing 
Furnace  at  1500®  F.  for  zVi  hours,  then  quench  in  oil.  Reheat  ai 
2300®  F.  in  a sale  bath  for  5 minutes,  and  again  quench  in  oil.  Draw 
at  350®  F.  in  an  oil  bath  and  air  cool.  Test  for  hardness  with  a 
Sdcroscope,  which  must  read  between  45  and  60.  (Roughly  equi- 
valent to  Rockwell  C 33  to  C 44.) 


Springfeld  Receivers  and  Bolts  from  Serial  No.  1,275,767  to  No. 
1,532,878. 


Material: 


Nickel  Steel  WD 
Carbon 
Manganese 
Nickel 
Sulphur 
Phosphorus 


2340. 

•35% 
.50%  to 

3.25%  to 

Not  over 

Not  over 


4570 

.80% 

3-75% 

.04% 

.04% 


Receiver  Sieels  and  He.\t  Treatment  227 

Treatment:  Quench  from  1600®  F.  and  dtiw  in  sodium  nitrate  at 
600^  F.  for  30  minutes. 

Receivers  £md  Belts  for  rifles  having  serial  numbers  over  3,000,000, 
of  World  War  II  mamifaciure. 

Material:  Until  March,  1942,  Nickel  Steel  WD  2340,  as  above. 

Treatmciir:  Anneal  in  charcoal  at  1450^  F.,  cool  in  furnace.  Heat 
ill  carburizing  salt,  1425®  to  1450®  F.;  quench  in  oil.  Temper.  Case  1 
depth,  .003  inch  to  .005  inch.  Rockwell  C 42  to  C 47  for  core. 

On  March  4,  1942,  the  use  of  WD  Steel  No.  4045  was  authorized; 
this  had  the  following  composition. 


Carbon 

40% 

to 

.56% 

Manganese 

.70% 

CO 

IX>0% 

Molybdenum 

.20% 

to 

.30% 

Sulphur 

Not  over 

.05% 

Phosphorus 

Not  over 

•04% 

Treatment:  Anneal  in  charcoal,  cool  in  furnace.  Heat  in  carbur* 
izing  salt  at  1475®  to  ijoo^  F.;  quench  in  oil  Temper.  Case  depth, 
.003  inch  to  .005  inch.  Rockwell  C 42  to  C 47  for  core. 

On  July  5,  1942,  the  use  of  an  additional  steel,  namely  WD  No. 
8620  Modifled,  was  authorized.  The  composition  of  this  steel  was: 


Carbon 

•18%  to 

.15% 

Manganese 

.70%  to 

1.00% 

Nickel 

.20%  to 

.40% 

Cliromium 

.20%  to 

.4o7« 

Molybdenum 

.15%  to 

.25% 

Sulphur,  resulphurized 

to 

.07%  max. 

Phosphorus  1 

Not  over 

.04% 

Grain  Size  5 to  8 ASTM 

Ilardenability,  Jointny  C 

20  Rockwell,  minimum,  at  ^ 

inch  from  quenched  end. 

Treatment  for  bolt:  Normalize  before  machining.  Carburize  .012" 
to  .015";  oil  quench.  Temper  at  350^'  F.  Hardness,  Rockwell  D 62 
CO  D 70  on  barrel  of  bole. 

Treatment  for  receiver:  Normalize  before  machining.  Carburize 
.009"  to  .015";  oil  quench.  Temper  at  350®  F.  for  1 hour  at  heat. 
Rockwell  O 62  to  D 70  on  side  rail. 

M Rifles  of  Rock  Island  Make 

The  Barrel  was  made  of  Ordnance  Barrel  Steel  as  given  above. 
Receivers  and  bolts  from  serial  No.  1 to  serial  No.  283,507. 
Material:  Springfield  Armorj'  Class  C Steel 

Treatment:  Pack  in  charred  leather  pots.  Heat  at  t475°  to  1500® 
F.  for  3!^  to  4 hours.  Quench  in  oil. 


22$ 


Hatcher’s  Notebook 


Receivers  and  bolts  from  serial  No.  2H5,jo7  co  319,921. 

Marerial;  Springfield  Armorj-  Gass  C Seed. 

Treatment:  Anneal  at  F.  for  2 hours;  drop  to  1050^  in  the 

furnace,  remove  and  air  cool.  Harden  by  healing  at  1550"  10  1600^ 
F.  for  15  minutes  and  c|ucnching  in  Houghton’s  #2  c|ucnching  oil. 
Reheat  to  1425^^  F.  followed  by  quenching  in  oil.  W'ash  in  soda 
kettle.  Draw  in  oil  at  500^  F. 

Receivers  and  bohs  over  serial  No.  319,921. 

jVlaterial:  Both  Class  C Steel  and  Hot  Rolled  Nickel  Sted  Specifi- 
cations \VD  35  NS.  WD  35  NS  had  the  following  composition: 


Carbon 

.30%  to 

Manganese 

45%  to 

.50% 

Nickel 

3.2570  to 

i-75% 

Silicon 

.10%  <0 

■25% 

Sulphur 

Noe  over 

•05% 

Pho.sphonis 

Not  over 

.05% 

Treatment:  For  nickel  steel  bolts  and  receivers:  Heat  in  salt  batU 
at  1500'''  F.,  quench  in  oil,  and  draw  in  sodium  nitrate  at  600®  F.  for 
30  minutes.  Sdcroscopc  hardness  must  be  between  55  and  70 
(Roughly  C-41  CO  0*52  Rockwell). 

Ev/teld  Rifles 

Barrel  made  of  ‘‘Smokeless  Barrel  Steel”  specified  in  Ord.  Ramphlct 
No.  3098. 


Carbon 

•4>% 

■5S7c 

Manganese 

1.10%  CO 

‘•15% 

Silicon 

.20%  to 

•30/<' 

Phosphorus 

under 

.06% 

Sulphur 

under 

.06% 

Receiver  and  Bolt  made  of  Nickel  Seed”  specillcd  in  Ord. 

Pamphlet  No.  3098.  This  could  be  either  made  by  the  Acid  Process 
or  the  Basic  Process  with  compositions  as  follows: 


Acid  Process 

Basic  Process 

Carbon 

.30%  to 

•40% 

.55% 

.45%  ; 

Manganese 

.50%  to 

•70% 

.50%  CO 

.70% 

Nickel 

5.00%  to 

5*75% 

3.25%  to 

1-75% 

Silicon 

.10%  CO 

.20% 

Phosphoru> 

under 

.05% 

under 

•o}5% 

Sulphur 

under 

.035% 

under 

.05% 

Receiver  Steels  and  Heat  Treatment  229 

U.  S.  Caliber  jo  M-i  Rifle  (Gar and) 

Barrel. 

Material:  WD  Steel  No.  4150  Modified,  with  coiiiposidon  as  given 
below: 


Carbon 

.45%  10 

.50% 

Manganese 

.60%  to 

.90% 

Chromium 

.80%  CO 

1.10% 

Molybdenum 

.15%  to 

-Z5% 

Silicon 

.15%  CO 

•J5% 

Phospfiorus 

Not  over 

.04% 

Resulphurize 

to  .04%  to 

•09% 

Treatment:  Before  imehining  normalize  if  necessary.  Oil  qnendi 
from  1575^  to  1675®  1\  Temper  nor  less  than  2 hours  to  meet  physical 
properties  as  follows: 

Tensile  Strength,  130,000  Ihs.  per  s<].  in. 

Yield  Strength,  uo,ooo  lbs.  per  sq.  in. 

Elongadon  in  2 inches,  i6%  minimum. 

Reduction  of  area,  50%  minimum. 

Brinell  hardness,  2^9-311  (Equivalent  to  Rockwell  C-28  to  C-34). 
Process  stress  relief  if  required  not  less  than  t hour  at  1000®  F. 

Bolt. 

Material:  (Prior  to  March,  i942)-VVD  Steel  No.  331:. 

Manganese  .30%  to  .60% 

Nickel  / 3*75% 

Chromium  J.25%  to  1.75% 

Carbon  Not  over  .17% 

Sulphnr  Nor  over  .05% 

Phosphorus  Not  over  .04% 

Material:  Authorized  July  5,  1942,  WD  Steel  No.  8620.  Modified, 
with  composition  as  given  above  under  .Mi 903  rifle. 

Treatment:  Normalize  before  machining.  Carburize  .015"  to  .020” 
at  i6uo®  F.;  oil  quench.  Temper  1 hour  at  325^  F.  Rockwell  C 55 
to  C 59  on  locking  lugs  and  rear  end  of  bolt. 

Receiver. 

Material:  Early  production:  WD  Steel  No.  3iis« 

Carbon  .10%  to  .20% 

Manganese  -30%  to  .60% 

Nickel  1.00%  to  1.50% 

Chromium  *45%  *75% 

Sulphur  Not  over  .05% 

Phospliorus  Not  over  .04% 


Hatchf-r’s  Nciteijook 


230 

Material:  Intermediate  Production:  WD  Steel  No.  3120. 

Carbon  .15%  to  .25% 

Manganese  «50%  to  JHo% 

Nickel  1.00%  to  1.50% 

Chfomhim  -45%  ^ *75% 

Sulphur  Not  over  .05% 

Phosphorus  Not  over  .05% 

Material:  After  July,  1942,  WD  No.  8620  .Modified,  same  as  for 
the  bolt. 

Treatment:  Carburize  .012"  to  .018"  at  1600^*  F.;  oil  quench  temper 
I hour  at  480®  1'*.  Rockwell  D 59  to  D 67. 

U.  S.  Coliber  Carbine  M-i 

Barrel. 

Material:  WD  No.  1350  Special- (Carbon  .50  to  .60%;  rcsulphur- 
izccl  to  .04%  CO  AO%\  Fine  grain,  gun  quality,  billets  macro-etch  in- 
spected y Alternate,  WD  No.  1550  Modified. 

W.  \y  No,  1350  Special  as  Specified  Above. 

Carbon  *50%  to  .60% 

Manganese  >*35%  co  1.65% 

Silicon  *15%  Co  .35% 

Resulphurized  .04%  to  .10^^ 

Phosphorus  Not  over  045!;^ 

Treatment:  Normalize  before  machining  if  necessary.  Oil  quench 
1350^  CO  1375"  F.  I’cmpcr  not  less  than  2 hours  at  heat  to  physical 
properties  specified  in  U.  S.  Army  Spec.  37- 107-25.  (Tensile  strength, 

1 1 0,000  lbs.  per  sq.  in.;  yield  point  80,000  Ihs.  per  sq.  in.;  elongation 
in  2 inches,  18%  minimum;  reduction  in  aica,  45%  minimum;  Brinell 
229-277.) 

Receiver  and  Boh. 

Material:  WD  4:40  Special- (Rcsulphurizcd  .04%  to  .09%;  fine 
grain,  gun  quality,  billet  macro-ctch  inspection  required.) 

^rbon  .35%  to  .45% 

Manganese  .70%  to  1.00% 

Phosphorus  Not  over  .04% 

Sulphur  .04%  to  .09%  ; i\r\i  iiili 

Chromium  .80%  to  1.10%^  ^ r ' ' 

Molybdenum  *15%  to  .25%  i-  r 

Treatment,  Bolt:  Norinalize  before  machining.  Preheat  700 F.; 
oil  quench  from  1550*’  F.  Temper  2 hours  at  heat,  not  less  than 
37  5 F.  and  not  more  than  45 o'"  F.  Rockwell  C 48- >4. 

iVeatmenr,  Receiver:  Same  as  bolt  except  tejnper  i hour  at  heat 
to  Rockwell  hardness  specified,  that  is  C 38  45. 

German  Mauser  Ge^  9S 

Analysis  of  the  metal  taken  from  several  bolts  and  receivers  indi- 
cates that  they  are  made  of  plain  carbon  steel  sitiiilar  to  SAE  No. 
i^35i  which  has  carbon  •'^0%  to  .40%  and  manganese  .60%  to  .90%. 


Rf.cfi\t,r  Stff.i5  axd  Heat  Treai  atj-m 


231 


Japanese  6.$  nnn.  Arisaka 

Several  bolts  and  rec: elvers  analy^^d  appear  to  be  made  of  ordinary 
carbon  steel  similar  to  SAE  No.  10K5  which  has  carbon  ,Ho%  to  .90^^ 
and  manganese  .M'/o  to  .90%. 

Steel  Specification  ^mnbcYs 

The  reader  has  noted  that  the  steels  used  in  recent  years  for  rifle 
manufacture  arc  defined  above  in  terms  of  SAE  or  WD  numbers. 

The  SAE  numbers  refer  to  standard  specifications  issued  bv  the 
Society  of  Automotive  Engineers  and  published  in  the  SAE  handbook 
and  in  other  engineers  handbooks  such  as  Machinery's  Handbook  and 
Kent's  Mcckesnical  Engineer's  Handbook. 

Much  valuable  information  on  the  composition,  physical  properties, 
recommended  uses,  and  appropriate  heat  treatments  of  allov  steels  may 
be  obtained  from  the  SAK  handbook  and  the  mechanical  engineers 
handbooks  mentioned  above. 

The  steels  defined  under  War  Department  or  nvimber  have 

in  general  the  same  composition  as  steels  with  the  corresponding  SAE 
numbers.  However  it  is  the  practice  to  use  Wl)  numbers  in  official 
specificacions,  as  SAE  comjK)sitioni,  nor  being  under  the  control  of 
the  War  Department  might  be  changed  without  their  knowledge,  tluis 
involving  a change  in  the  War  Department  specifications  over  which 
they  would  luve  no  control.  In  addition  under  the  WD  specifications 
the  percentage  of  one  or  more  of  the  constituent  alloy.s  may  be  varied 
or  held  to  closer  linfits  to  meet  the  exacting  rc(]uirements  of  gim 
nmnufacture. 


The  numbers  then  selves  arc  assigned  according  to  a system  in  which 
the  first  digit  refers  to  the  type  of  steel,  the  second  indicates  the 
percentage  of  the  main  alloying  ingredient  while  the  last  tw'o  figures 
give  the  carbon  concent  in  points,  that  is  in  hundredths  of  a per  cent. 


The  h 


to  the  meaning  of  the  first  digit  is  as  follows: 


t 

2 

3 

4 

5 

6 

7 

8 

9 


indicates  carbon  steel 

indicates  nickel  steel 

indicates  nickcbchroniiuin  steel 

indicates  molybdenum  steel 

indicates  chroiuiuiii  steel 

indicates  chromium -vanadium  steel 

indicates  tungsten  steel 

indicates  nickel-chromium  molybdenum  steel 

indicates  silico-nian^ancsc  steel. 


Applying  the  system  given  above,  it  can  be  deduced  ihar  WO 
steel  Slo.  2340  of  which  so  many  M i<;o3  bolts  and  receivers  were 
made  is  a nickel  steel  with  some  3%  (3.25^^  to  3 7 5%)  nickel  and 
some  40  points  (*35%  to  45%)  carbon. 


X 

Headspace 

WHEN  1 first  became  accjuainted  with  sporting  rifles,  hunters 
were  plagued  with  a certain  very  distressing  malfunction,  which 
would  often  occur  right  in  the  middle  of  a hunting  trip,  and  would 
usually  put  the  gun  out  uf  action  until  the  user  could  get  back  to 
a gunsmith. 

This  trouble  was  a separation  of  the  cartridge  case,  usually  about 
a quarter  to  a half  an  inch  ahead  of  the  rim.  When  the  breech  was 
opened,  the  head  of  the  cartridge  would  be  pulled  out  by  the  ex- 
tractor, but  the  body  of  the  case  would  remain  tightly  wedged  in 
the  chamber,  effectively  preventing  the  insertion  of  another  round 
of  amiinmicion. 

The  remedy  that  was  most  often  resorted  to  was  to  carry  in  the 
kit  a small  device  called  a broken  shell  extractor,  sold  by  most 
sporting  goods  stores.  Wl»cn  by  bad  luck  a cartridge  separated  the 
user  would  insert  the  broken  shell  extractor  into  the  chamber  and 
close  the  bolt;  on  opening  it  again,  the  extractor  would  pitll  our  the 
broken  shell  extractor,  together  with  the  front  half  of  the  ruptured 
cartridge  case.  This  was  of  course  a cure  but  not  a prevention. 

In  every  instance,  the  cause  of  this  trouble  was  whar  is  known 
as  excess  headspace,  but  the  term  “headspace”  was  mrely  heard  in 
those  days,  and  nobody  ever  talked  or  wrote  of  it.  However,  Myles 
change  in  the  shooting  world  as  fast  as  they  do  anywhere  else,  and 
in  the  last  few  years  a lot  of  things  have  been  blamed  on  headspace. 

In  the  years  just  before  World  War  II,  it  became  the  fashion  for 
gunsmiths  all  over  rhe  country  to  originate  “wildcat”  cartridges  by 
“improving”  some  factory  cartridge,  and  then  giving  it  a fancy 
designation  with  the  originator^  own  name  added. 

The  improvement  frequently  involved  necking  down  the  standard 
case  to  take  a smaller  bullet,  and  it  almost  always  provided  increased 
powder  capacity  by  expanding  the  ease  into  an  enlarged  chamber. 
Usually  in  the  process  the  shoulder  was  made  considerably  .sharper 
than  it  was  in  the  original.  This  sharper  shoulder  is  supposed  to  hold 
back  the  powder  as  the  bullet  moves  forward  in  the  bore,  thus  giving 
the  powder  better  burning  characteristics. 

Making  the  shoulder  sharper  does,  of  course,  add  powder  space, 
and  thus  make  possible  higher  velocities,  accompanied  of  course  bv 
the  inevitable  higher  pressure.  It  is  conceivable  that  the  sharper 
shoulders  do  help  the  burning  of  the  powder,  but  as  far  as  I can  see, 
this  has  not  been  proved.  Very  carefully  conducted  experiments, 

232 


Headspace 


233 

using  chronographs  and  pressure  gauges,  with  cases  of  the  same  caliber 
and  cubic  capacity,  but  with  shoulders  of  different  slopes  have  failed 
CO  show  that  the  shape  of  the  shoulder  makes  any  difference  at  all. 

With  the  increased  powder  capacity  that  these  wildcat  cartridges 
had,  it  was  inevitable  that  increased  pressures  would  be  obtained. 
Usually  the  originator  of  one  of  these  cartridges  had  no  facilities 
for  taking  pressures,  and  depended  entirely  on  the  notoriously  un- 
reliable method  of  judging  pressures  by  the  appearance  of  the  primer. 

In  many  of  these  wildcats,  the  actual  pressures  obtained  with  some 
nf  the  recommended  loads  must  be  fantastic,  and  it  was  no  wonder 
chat  the  usual  crop  of  troubles  with  gas  leaks  and  blown  cases  oc- 


Figure  1.  He;uUpace  id  a rifle  lining  a .22  rimliie  cunridge. 


curred.  For  these  the  mysterious  headspace  formed  a convenient 
scapegoat,  and  the  term  became  a fashionable  explanation  for  almost 
anything  unplea.sanr  connected  with  shooting  these  souped  up  loads. 

Just  what  is  this  business  of  headspace  that  so  many  shooters  are 
worried  about  these  days?  Let's  get  back  to  fundamentals  a bit,  and 
follow  the  thing  through  from  the  b^inning  of  the  term. 

Early  cartridges  all  had  a rim,  like  the  .22  caliber  long  rifle  car- 
tridges shown  in  Fig.  1.  When  such  a cartridge  is  placed  in  rhe 
barrel  of  a rifle  or  pistol,  the  rim  is  the  only  thing  that  keeps  it  from 
going  all  the  way  in.  As  can  be  seen  in  the  diagram,  the  rim  stops 
against  the  rear  face  of  the  barrel.  When  the  bolt  is  closed  it  comes 
up  against  the  head  of  the  cartridge.  In  front  of  the  cartridge  rim  is 
the  rear  face  of  the  barrel  and  behind  it  is  the  front  face  of  the  bolt. 
Between  the  bolt  and  rhe  barrel  there  must  be  enough  space  to 
accommodate  the  head  or  run  of  the  cartridge,  and  this  is  the  head- 
space. 

Ordinary  revolver  cartridges  arc  mostly  of  the  rimmed  variety, 
chough  there  are  some  notable  exceptions,  such  as  the  rimless  ,45 
automatic  pistol  cartridge  ii.sed  in  the  Model  of  1917  Cole  and  S. 
& W.  revolver.  In  some  revolvers  the  cartridge  rims  rest  against  the 
rear  face  of  the  cylinder,  and  in  these  tlie  headspace  is  the  distance 


Hatcher’s  Notebook 


^34 

from  che  cylinder  to  the  recoil  plate,  which  is  that  part  of  the  frame 
which  supports  the  cartridge  head  during  firing. 

Some  revolvers,  especially  those  made  for  riiii-firc  cartridges  and  for 
the  ultra-high-prcssure  center-fire  loads^  liave  the  chambers  counicr- 
bored  so  that  the  cartridges  go  in  almost  flush  with  the  rear  end  of 
the  cylinder,  and  the  cartridge  heads  are  each  surrounded  by  a solid 
ring  of  metal.  In  these  the  headspace  is  the  distance  from  the  recoil 
plate  to  che  shoulder  against  which  the  rim  seats  when  the  cartridge 
is  in  che  chamber.  In  other  words,  just  the  rim  thickness  plus  the 
necessary  tolerance  to  accommodate  ammunition  of  different  makes. 

Most  revolver  cartridges,  such  as  for  example  the  .38  special,  are 
straight  sided,  just  like  che  .zi  rim-lirc,  and  in  these  there  is  noihing 


but  the  rim  to  prevent  the  cartridge  from  going  all  the  way  into  che 
cylinder.  On  tne  other  hand,  most  high  powered  rifle  cartridges  of 
the  rimmed  variety*  such  as  for  example  the  .30-40  Kiag,  otherwise 
known  as  the  .30  tJ.  S.  Army,  shown  in  Fig.  2 are  tapered  or  bottle- 
necked so  they  couldn’t  go  very  far  in  even  if  they  didn’t  have  a 
rim.  These  always  have  a clearance  at  the  shoulder,  as  shown  in  the 
sketch,  so  that  the  rim  will  be  sure  to  bear  on  its  seat  before  che 
shoulder  can  come  into  contact.  When  such  a cartridge  Is  fired,  the 
brass  expands  until  the  case  fits  the  chamber  at  ail  points,  hence  in 
reloading,  the  clearance,  above  mentioned,  docs  nor  exist.  .As  long  as 
the  reloaded  cases  are  used  in  the  same  rifle  this  makes  no  difference. 
However,  if  used  ia  another  gun  of  the  same  caliber,  they  might  bear 
at  the  shoulder  before  the  rim  scats,  and  difficulty  would  then  be 
experienced  in  closing  the  bolt. 

When  repeating  rifles  having  box  magarincs  first  came  into  use  it 
w'as  found  that  the  rims  on  the  cartridges  made  it  difficult  to  pro- 
duce magazines  that  would  feed  the  cartridges  smoothlv.  To  over- 
come this  difficiiltv,  two  new  types  of  cartridges  were  produced, 
which  look  much  alike  to  a casual  inspection,  but  which  really  are 
quite  different  in  principle.  These  are  the  rimless  type,  and  the 
.semi-rim,  or  as  it  is  .sometimes  called,  the  senii-rimicss. 

The  semi -rim  type  is  seen  in  such  well-known  cartridges  as  the 


Headspace 


235 


figure  3.  Headspace  ^ith  a semi-rim  pijiol  cartridge,  such  a»  the  .38  ACP. 


Figure  4.  licadspacc  wiib  a rimless  pistol  cacuidge — the  .45  ACP. 


.351  and  .40c  Winchester  self-loading  and  chc  .25,  .32  and  .3^  A.C.P., 
the  latter  of  which  is  illustrated  in  Fig.  3.  ‘llic  rim  Ls  made  very 
little  larger  than  rhe  body  of  the  cartridge,  and  there  is  a groove 
or  cannelure  cur  into  the  body  just  forward  of  the  rim,  for  the 
extractor  to  fir  into.  The  sciiii-riin  type  works  )usc  like  the  rim 
cartridge.  Even  though  the  semi-rim  is  ever  so  liede  larger  chan  the 
body  of  the  case,  this  little  is  still  enough  to  scop  ic  positively  at  the 
right  place. 

Here  also  headspace  is  a distance  equal  to  the  thickness  of  the  rini 


HAir.HF.R’s  Notf.book 


236 

plus  tlie  necessary  tolerances  to  enable  different  makes  of  gun  and 
cartridge  to  fit  together. 

The  true  rimless  cartridge  has  a head  which  is  nu  larger  than  the 
body  of  the  cartridge  is  at  some  point  further  forward.  It  has  a 
groove  or  cannelure  cut  around  it  just  forward  of  rhe  rim,  for  the 
extractor  to  hook  into.  As  the  rim  is  no  larger  chan  the  body,  it 
cannot  be  used  to  limit  the  forward  motion  of  the  cartridge  when  it 
is  seated  in  the  chamber,  and  this  must  be  accomplished  in  some 
other  manner.  With  the  .45  A.C.P.  cartridge  this  is  done  bv  leaving 
the  forward  end  of  the  cartridge,  that  is,  the  mouth,  stjuare,  instead 
of  crimping  it  onto  the  bullet  as  is  done  with  most  other  pistol  or 
revolver  cartridges.  A sc)iiare  shoulder  or  ledge  is  left  at  the  front 
end  of  the  chamber  and  the  mouth  of  the  case  scats  against  this  .st]iiarc 
ledge.  Sec  Fig.  4. 


Figure  5.  HcaJsimc  a cartridge,  ^uch  ifi  the  .30* *06. 


As  there  is  nothing  for  the  head  or  rim  to  scat  against,  the  true 
headspace  in  the  old  meaning  of  the  term  has  no  significance,  and 
when  we  want  to  determine  tolenmcos  as  to  cartridge  seating  we 
have  to  measure  all  the  way  from  the  breech  block  to  the  shoulder  at 
the  front  of  the  chamber.  For  convenience,  we  now  call  this  distance 
“headspace”  also,  when  speaking  of  giuis  using  ritiiless  cartridges. 

When  the  Mauser  repeating  rifles  were  designed,  the  inventor  in- 
troduced the  well-known  rimless  rifle  cartridges,  of  which  the  .30  '06 
is  an  example.  As  shown  in  Fig.  5,  thc>c  cartridges  sc.it  on  the  tapered 
shoulder  which  connects  the  body  of  the  cartridge  to  the  neck. 
Hence,  in  the  high  powered  rimless  rifle  cartridge  the  distance  from 
the  face  of  the  closed  bolt  to  some  reference  point  on  the  shoulder  in 
the  forward  pan  of  the  chamber  is,  for  convenience  and  for  want  of 
a better  term,  called  the  “headspace.”  Note  that  the  principal  contact 
which  positions  the  cartridge  in  the  chamber  is  at  the  same  point 
where  a clearance  is  purposely  left  in  the  rimmed  variety. 

As  a pracficai  matter,  it  is  impossible  to  measure  this  kind  of  head- 
space  without  special  gauges,  because  the  shoulders  both  on  the 
cartridge  and  in  the  chamber  blend  into  the  slopes  ahead  of  and 
behind  them,  and  there  are  no  sharp  edges  to  measure  from.  Actually 


MASTER  RING  SET-UP 


FOR  PRODUCING  "L" 


HEADSPACE  GAGE  FOR  U.  S.  SERVICE  RIFLES  CALIBER  30. 

'*L”  is  the  headspace,  aad  is  the  bfeechiaB  space,  used  for  purposes  of  compuutioo  only;  it  is  equal  to  "L”  plus  .714  inch, 
Values  of  axe  as  follows: 

Foe  manufacture  of  the  V.  $.  Rifle  Caliber  .30  M 1:  mioimum,  1.942;  fimimum.  1.944. 

Fot  the  manufacture  oi  other  rifles;  minimum,  1.940;  maximum,  1.944. 

As  a maAimum  gage  for  inspection  of  overhauled  rifles:  1.946. 

For  inspection  as  a field  headspace  limit  foe  serviceable  rifles:  1.950. 

If  desired,  a scmi-circulac  groove  may  be  cut  in  the  bead  of  the  gage  to  clear  the  ejector  in  the  M 1 Rifle,  and  thus  avoid  having  to 
remove  the  ejector  when  headspadng  diese  rifles. 


Hatchers  Not£BOOK 


238 

the  1.940  inch  minimum  to  1.944  i^^h  maximum  headspace  of  the 
’03  Springfield  rifle  is  measured  to  a hypothetical  intersection  which 
does  nor  exist  and  can  only  be  located  bv  measuring  to  a given  point 
on  a ring  gauge  chat  firs  over  the  rapered  shoulder  of  a steel  gauge 
shaped  like  a cartridge.  This  will  be  berrer  undei*stood  by  reference 
to  the  official  drawing  for  the  .30-06  headspace  gauge,  which  is  shown 
herewith  in  simplified  form,  retaining  the  essential  dimensions  bxit 
omitting  many  confusing  cross  references. 

There  is  still  another  variety  of  cartridge,  and  that  is  the  belted 
type,  .such  as  is  used  in  the  [I.  & H.  Magmim  and  ocher  similar  rifle 
cartridges.  As  shown  in  Fig.  6,  it  is  really  a modified  rininicd 
cartridge,  having  a very  wide  and  very  shnlhnv  rim.  The  rim  is  not 


6.  Rchtd  cartridge  showing  headspace. 


high  enough  to  give  a good  place  for  the  extractor  to  take  hold,  so 
there  an  extractor  groove  cut  into  the  rim  itself.  To  explain  it 
another  way,  it  is  like  a rimless  carfridge  with  a slight  .step  just  ahead 
of  the  extractor  groove.  In  scaling  the  caitridge  this  step  comes  to 
rest  against  a slight  corresponding  ledge  in  the  cliamber.  This  gives 
the  same  effect  as  that  of  a rimmed  cartridge,  and  like  it,  always  has 
a clearance  at  the  shoulder  until  after  ic  has  been  fired  once. 

I have  cried  above  to  show  just  what  headspace  is.  The  next  ques- 
tion is  how  does  it  varv,  and  what  do  the  variations  do  to  the  func- 
tioning  of  the  gun. 

Taking  the  rim  fire  cartridge  first,  it  should  be  quite  obvious  that 
the  heacJspace  muse  not  be  less  than  the  thickness  of  the  rim.  If  it  is, 
the  rim  of  the  cartridge  will  be  .«Kjueczed  when  the  bolt  k slammed  or 
forced  shut,  and  premature  discharge  may  result. 

With  the  rim  fire  cartridge,  excess  headspace  will  result,  in  cfFeci, 
in  a shorter  firing  pin  blow,  and  thus  in  poor  ignition.  As  the  .22 
rim  fire  cartridge  is  notoriously  sensitive  to  irregular  ignition,  excess 
headspace  mav  result  in  variations  in  ignition  that  w ill  have  a very  bad 
effect  on  accuracy. 

With  straight  sided  cartridges  of  the  center  fire  variety,  such  as 
the  usual  pistol  cartridge,  headspace  that  Is  coo  small,  that  is,  less 
than  the  minimum  specified,  will  usually  make  it  impossible  to  close 


Heampacr 


239 


I the  breech  of  the  gun  after  it  is  loaded.  Xaturally  this  comlicion  does 
I not  often  occur  as  a gun  defect,  though  the  same  result  will  follow 
' the  tise  nf  a cartridge  with  a head  that  i$  coo  chick,  which  is  a 
trouble  sometimes  seen. 

With  these  cartridges,  the  principal  result  of  excess  headspace  is 
to  let  die  can  ridge  move  further  away  from  the  hrccch  block  when 
I it  is  struck  by  the  breech  block.  This,  in  elTcci,  gives  a shorter  firing 
pin  blow,  and  if  it  is  very  excessive,  ic  imy  cause  hang-fires  or  mis- 
fires. 

Thus  it  is  quite  possible  to  fire  the  .45  A.C.P.  cartridge  in  the 
•455  Web  ley  & Scott  self  loading  Pistol,  even  chough  with  this  gun 
and  cartridge  combination  there  is  about  inch  excess  headspace. 
If  the  cartridges  are  loaded  into  the  chamber  singly,  they  go  in 
so  far  that  neither  rhe  firing  pin  nor  the  extractor  can  reach  them, 
and  they  will  not  fire;  but  if  they'  arc  loaded  from  the  magazine,  they 
rise  up  under  the  extractor  hook  and  this  holds  them  dose  enough  to 
the  breech  block  so  chat  the  firing  pin  can  strike  the  primer,  and 
they  fire,  extract,  eject,  and  reload  just  as  if  they  were  intended  for 
this  gun,  in  spite  of  the  % of  an  inch  excess  headspace.  1 have  fired 
many  round.s  of  this  .45  Automatic  Colt  Pistol  amnuinirion  through 
the  .455  Wcblcy  and  Scott  Selfloading  Pistol. 

Likewise  the  9 mm  short,  or  .380  A.C.P.  cartridge,  which  is  .080" 
shorter  than  the  proper  9 mm  Parabellum  cartridge,  may  be  fired 
from  the  magazine  in  the  Luger  or  the  P-38,  but  this  little  cartridge 
has  insufficicnr  power  to  eject  and  reload,  so  the  .slide  must  be  pulled 
back  by  hand  after  each  shot.  I have  fired  m.iny  of  these  cartridges 
in  both  these  guns  with  no  trouble  as  long  as  they  feed  up  from  the 
magazine.  If  loaded  in  the  chamber  by  hand,  they  will  not  fire  be- 
cause the  extractor  will  not  catch  them  at  all  in  the  Luger,  and  cmly 
part  of  the  time  in  the  P-38. 

I have  also  fired  the  .455  Web  ley  Revolver  Cartridges  Mark  II  in 
the  .45  caliber  Colt  New  Service  Revolver  wirh  an  excess  headspace 
of  .037",  ami  I liavc  fired  the  .455  Automatic  Wcblcy  & Scocr  Pistol 
Cartridge  in  this  same  Colt  New  Service  45  with  an  exces.?  headspace 

rfo  * 

•025  . 

Likewise,  in  trying  everything  I could  think  of,  J have  fired  quite 
a few  .45  Automatic  Colt  Pistol  Cartridges  in  a Colt  New  Service 
Revolver  Caliber  .455,  with  an  excess  headspace  for  this  combination 
of  .05 1 

Ill  all  of  the  above  shooting,  ncciiracv  was  excellent,  ami  no  bad 
results  of  anv  kind  were  observed.  The  onlv  trouble  to  be  expected 
was  a possibility  of  hangfires  or  misfires  from  having  the  primer  too 
far  away  from  the  firing  pin,  but  even  this  did  not  occur. 

Shotgun  shells  come  in  the  category  mentioned  above,  of  rim 
cartridges  with  straight  sides  and  giving  low  maxiimim  pressures; 
usually  not  over  8000  to  10,000  pounds  per  square  inch.  A moderate 


Hatcher’s  Notebook 


240 

amount  of  excess  headspace  in  shot^ns  seems  to  make  little  or  no 
difference,  but  a large  amout^,  say  a tenth  of  an  inch  or  more,  is 
dangerous,  as  there  is  nothing  but  the  internal  base  wad  of  rolled 
cardboard  and  the  thin  brass  wall  to  hold  in  the  pressure  where  the 
shell  is  unsupported  in  the  space  between  the  end  of  the  barrel  and 
the  face  of  the  brccch. 

An  acquaintance  once  told  me  that  his  pnmp  action  shotgun 


FiguM  7.  Upper:  ShelJ  a/iw  6fiaa  with  normal  headspace  I.owei:  Shell 
fired  in  gun  H'ltb  one  tench  inch  excess  headspace. 


worked  hard,  and  chat  after  he  had  with  some  difficulty  extracted 
the  shells,  they  were  badly  bulged  just  ahead  of  the  rim.  I found 
that  he  had  assembled  his  gun  with  the  barrel  just  two  threads  for- 
ward of  being  fully  seated  in  the  receiver,  and  as  the  barrel  had 
twenty  threads  per  inch,  this  gave  liim  just  i/io  inch  more  head- 
space  than  the  gun  would  Iiave  liad  if  it  had  been  put  together 
properly. 

On  November  i,  ^946,  A1  Barr  of  the  American  Riilcimn  staff  was 
helping  me  to  pattern  some  shoguns,  and  we  got  to  discussing  tins 
question,  so  we  assembled  a pump  gun  in  this  inamicr,  and  fired  several 
shots  with  Federal  Monark  and  also  with  Federal  HiPower  loads. 
I fired  these  loads  myself  from  the  shoulder,  but  was  careful  to 
wear  my  Rayhan  shooting  glasses,  and  also  to  keep  my  forearm  out 


Headspace 


241 


from  under  the  ejection  opening,  just  in  case  the  head  of  one  of 
those  shells  should  fail  to  hold  the  pressure.  Patterns  were  the  same 
as  usual,  and  everything  worked  all  right,  except  that  extraction  was 
a trifle  hard,  tliou^h  not  excessive.  The  fired  shells  were  swelled 
OQC  as  shown  in  Figure  7,  but  they  held  together,  in  spite  of  the 
i/io  inch  excess  headspace,  and  no  liarm  was  done.  These  particular 
shells  have  a high  and  very  strong  inside  base  wad,  and  this  helped. 

It  should  be  noted  that  most  pump  action  guns,  such  as  the  Win- 
Chester  and  Remington  models  cannot  be  niis-assemblcd  this  way, 
the  designers  have  put  in  mechanical  devices  to  prevent  it.  There  is 
one  high  grade  pump  gun  in  which  this  can  be  done,  but  this  will 
be  corrected  in  the  near  future. 

With  bottlenecked  cartridges,  whether  riiti  or  rimless,  the  matter 
is  quite  difTerenc,  The  powder  gas  pushes  back  on  the  base  of  the 
cartridge  with  several  thousand  pouuds  pressure,  and  exactly  the 
same  coral  pressure  is  exerted  in  a forward  direction,  part  of  it  on 
the  base  of  the  bullet  and  the  rest  on  elte  capered  inside  of  the  case 
body  and  shoulder.  This  pressure  forces  the  forward  part  of  the 
cartridge  case  tight  against  the  shoulder  of  the  chamber  and  at  the 
same  time  drives  the  head  of  the  case  back  against  the  face  of  the 
bolt.  If  there  is  excess  headspace,  the  case  will  be  stretched;  if  the 
he.nispacc  is  coo  excessive,  the  case  will  be  separated  or  ruptured  at  a 
point  about  */j  inch  from  the  head  where  the  thick  brass  in  the  i)ase 
0/  the  case  begins  ro  thin  out  as  it  joins  the  walls.  When  the  gun  is 
opened,  the  base  of  the  cartridge  will  come  out  wirit  the  extractor, 
but  the  forward  part  of  the  case  will  remain  wedged  in  the  chamber 
and  the  gun  cannot  be  used  again  until  tliis  is  removed. 

Lever  action  rifles  arc  rather  more  subject  to  this  trouble  than  are 
bolt  action,  as  the  lever  actions  stretch  and  spring  more.  With  good 
strong  actions  and  moderate  pressure  loads,  and  especially  if  the 
shooting  glasses  are  worn,  this  trouble  is  not  particularly  dangerous, 
but  is  annoying  and  inconvenient.  Very  little,  if  any,  gas  escapes  to 
the  rear,  because  the  back  end  of  the  cartridge,  which  remains  in 
the  chamber,  acts  as  a seal.  In  fact,  it  is  just  such  short  brass  cups 
that  the  Germans  have  for  years  used  as  the  breech  seals  in  their 
heavy  artillery,  instead  of  the  “mushroom  head*’  and  gas  check  pad 
of  our  big  gun  system. 

It  just  happens  that  I have  had  an  unusual  amount  of  personal 
experience  w'ith  this  matter  of  excess  headspace  and  separated  cases. 
In  1916  and  ’17  as  Captain  of  Ordnance,  I had  charge  of  the  Army 
.Machine  Gun  Schools,  first  on  the  Mexican  Border,  then  at  Spring- 
field.  In  those  days,  Frankford  Arsenal  made  the  ,3o-’o6  cartridge 
case  of  very  hard  brass  to  make  extraction  easier  and  to  improve  die 
functioning  in  machine  guns.  These  bard,  brittle  cases  gave  marvelous 
operation  when  the  headspace  was  normal  but  would  separate  in  a 
hurry  if  the  headspace  got  the  least  bit  over  the  limit.  The  automatic 


Hatcher’s  Notebook 


242 

machine  rifle,  Caliber  .30,  M 1909,  had  detachable  barrels,  held  on  bv 
a nut  which  could  be  nghecned  witli  a spanner.  Lei  this  nut  get  the 
least  little  bit  loose  and  the  case  ruptured  and  the  gun  jammed 
because  the  following  cartric^c  could  not  chamber  fully.  The  rup- 
tured case  extractor  was  about  the  most  important  part  of  each 
gunner's  kit.  1 experimented  until  I found  how  to  fix  the  guns 
they  would  fire  a few  shots,  then  chop  off  a case  and  jam. 


FiRur«  Results  of  excess  headspace.  Top:  Stretched  case  due  lu  moderately 
excessive  headspace.  Center:  laupieni  separation  due  to  greater  headspace  than  top 
picture.  Bottom:  Rupture  due  co  very  excessive  headspace. 


Every'^  student  had  this  situation  dirown  at  him  repeatedly  until 
he  could  correct  it  in  the  dark.  In  my  own  experimental  firing  I 
encountered  at  least  a couple  of  hundi*ed  such  separations,  and  every 
one  of  my  several  thousand  students  had  to  experience  and  correct 
this  situation  several  times  and  I never  saw'  enough  gas  escape  to 
hurt  any  one.  However,  bear  in  mind  we  were  using  the  old  .30-06 
cartridge  with  150  grain  bullet,  2700  feet  per  second  and  not  over 
50,000  pounds  pressure.  With  some  of  the  super  high  intensity  loads 
that  are  being  used  today,  any  headspace  over  riie  normal  can  he 
dangerous. 

In  1917,  Frankford  Arsenal  began  making  the  cases  much  softer, 
just  to  get  away  from  these  separations.  The  soft  cases  have  been 


Headspace 


H3 

continued  up  ro  the  present  time,  except  for  a few  lots  marked 
“R”  (for  rifle),  and  intended  for  the  National  Matches. 

These  softer  cases  stick  badly  in  a hand-oj>cr;?tcd  rifle  when  it 
heats  up  in  rapid  hre,  but  will  stand  a tremendous  anuumr  of  stretch- 
ing without  an  actual  rupture. 

Symptoms  of  excess  headspace  can  be  plainly  seen  on  the  cartridge 
case  if  you  know  what  to  look  for— see  h'ig.  8.  The  first  thing  that 
happens  is  a stretch,  which  is  a bright  zone  extending  aU  round  the 
case  about  a half  inch  from  the  base.  As  the  headspace  gets  worse, 
the  stretching  shows  up  in  a more  pronounced  manner,  and  the 
beginning  of  a crack  running  around  the  case  may  be  seen.  The  next 
step  is  the  actual  separation. 

One  situation  in  which  excess  headspace  can  become  dangerous  is 
when  the  receiver  and  bolt  are  glass-hard  and  very  brittle,  as  was 
sometimes  the  case  with  Springfield  receivers  of  the  old  heat-treatment 
made  before  19  c 8.  Like  a razor  blade,  these  arc  strong  to  any  direct 
pull,  but  have  low  resistance  to  shuck.  Excess  headspace  allows  the 
bolt  to  have  a certain  amount  of  play.  When  the  explosion  occurs, 
the  bolt  can  move  back  and  then  stop  suddenly  against  the  locking 
shoulders,  striking  them  a smart  blow  which,  with  one  of  these  old 
glass-hard  receivers,  may  cau.se  it  to  shatter. 

On  the  other  hand,  with  receivers  which,  instead  of  being  hard 
and  brittle,  are  tough  and  clastic  like  the  double  heat-treated  Spring- 
fields  numbered  over  800, o<x)  and  the  nickel  steel  Fn fields  and  late 
Springfields,  such  a hammering  by  the  bolt,  due  to  excess  headspace, 
may  caii.se  a gradual  stretching,  but  cannot  cause  either  rhe  bolt  or 
the  receiver  to  shatter. 

Of  course  the  very  toughest  problem  as  far  as  headspace  is  con- 
cerned is  presented  by  the  service  cartridge,  and  other  cartridges 
which  like  it,  seat  on  a conical  shoulder  of  chin  brass.  This  docs  not 
form  a very  definite  stopping  surface,  for  it  is  quite  possible  if  force 
is  applied  to  drive  the  cartridge  further  in  after  it  has  seated  itself, 
and  any  over-drive  is  in  cflcct  so  much  excess  headspace.  In  World 
War  1 we  had  an  aircraft  machine  gun  in  which  che  luccch  was 
slammed  home  rather  violently  bv  a strong  spring,  and  in  order  to 
prevent  this  overdrive  of  the  cartridge  from  causing  headspace  diffi- 
culties, the  chamber  of  this  gun  was  made  eleven  thousandths  shorter 
than  the  specifications  for  the  minunum  chamber  of  the  service  rifle. 
That  meant  that  the  slam  of  the  breech  mechanism  had  to  drive  the 
cartridge  in  at  least  eleven  thousandths  beyond  its  first  contact  with 
the  seating  shoulder  before  the  breech  could  even  close. 

Our  rifleinen  are  used  to  measuring  the  headspace  of  their  rifles  by 
thousandths,  and  are  prone  to  become  very  much  alarmed  if  the  head- 
space gauges  two  or  three  choasandths  of  an  inch  more  than  the 
normal  ma?dmum.  This  Ls  a good  safe  attitude  to  take,  but  ir  is  some- 
thing like  measuring  cord  wood  with  a micrometer.  When  you  have 


Hatchfrs  Notebook 


244 

measured  your  headspace  down  co  the  last  thousandth,  you  may  load 
your  gun  with  a slam  of  the  bolt  and  drive  the  cartridge  five  or  six 
thousands  beyond  the  point  tvherc  it  first  seats.  Moreover,  the  mini' 
mum  service  cartridge  is  six  thousandths  shorter  than  the  maximum; 
in  effect  that  gives  you  sue  thousandths  more  headspace  than  you 
w’ould  have  w'ith  a maximum  cartridge  under  the  same  gun  conditions. 

Captain  Melvin  M.  Johnson  of  the  United  States  Marine  Corps, 
the  inventor  of  the  famous  semimuiomacic  rifle  and  light  machine 
gun  that  bear  his  name,  first  called  my  atcctuion  to  rhe  variation  in 
seating  of  the  cartridge  and  the  consequent  variation  in  accuracy 
chat  can  result  from  differences  in  the  speed  and  force  with  whidi 
the  bolt  is  manipulated  in  loading. 

In  an  authoritative  article  on  this  subject  in  The  American  Rifkmiav 
for  March,  1947,  Captain  Johnson  stated  in  [wre: 

“Now  when  the  bolt  or  breechblock  reaches  the  point  of  full  lock- 
ing, it  may  still  go  fonvaul  until  it  is  stopped  by  the  barrel  slioulder 
or  some  other  stopping  point.  The  rear  surfaces  of  the  lockbg  lugs 
bear  on  the  shoulder  surfaces  in  the  receiver  to  prevent  the  bolt  from 
being  blown  backward,  but  there  is  necessarily  some  clearance  on 
rhe  forward  side  of  the  locking  lugs.  Assuming  the  achievement  of 
a perfect  condition,  i.e.,  no  clearance  forward  of  the  locking  lugs, 
the  forward  motion  of  rhe  bolt  would  be  stuped  exactly  at  the 
point  where  the  lugs  were  coinplcrely  engaged.  Yo  obtain  this  perfect 
condition,  the  forward  clearance  on  the  bolt  wouki  have  to  be 
exactly  zero.  Rather  a job  of  work  to  hold  this  clearance  to  precisely 
zero  in  mass  production.  Assume  therefore  a clearance  of  .006  inch 
forward  of  the  locking  lugs.  The  mechanical  headspace  of  the  .jo 
caliber  M 1903  rifie  is  specified  as  1.940  to  1.946,  or  an  allowance 
of  .oort  inch.  In  addition  we  have  the  clearance  of  .006  inch  just 
niemioiicd,  and  moreover  there  is  allowed  a tolerance  of  .006  inch 
in  the  length  of  the  cartridge  from  head  to  shoulder. 

^Therefore,  what?  The  answer  is  that  a rimless  cartridge  slammed 
forward  with  force  will  be  driven  into  the  chamber  until  the  bolt 
stops.  Then  the  bolt  will  lock.  The  forward  clearance  may  permit 
the  bolt  to  drive  the  cartridge  a distance  up  to  .006  inch  beyond  its 
intended  stopping  point,  forcibly  deforming  or  resizing  the  cartridge 
shoulder  in  the  process.  The  result  may  be  a working  headspace  of 
up  to  .012  inch  above  the  theoretical  minimum. 

“Now  take  the  case  of  a gun  with  greater  headspace  and  clearance 
figures  than  those  mentioned  above.  Consider  mechanical  headspace 
of  1.950  inch,  or  .010  inch  above  minimum,  and  forward  clearance 
of  .020  inch.  Such  a combination,  when  the  holt  is  slammed  home 
with  force,  can  produce  a total  of  .030  inch,  or  a full  thirty  second 
of  an  inch  above  minimum  headspace.*’ 

This  drive-in  condition  is  obviated  to  some  extent  because  the  holt 
is  arrested  and  commences  to  rotate  on  the  extracting  cam  shoulder 


Hcadspac£ 


245 


before  the  cartridge  is  fully  chambered,  'fliis  tends  to  squeeze  the 
cartridge  slowly  home.  Nevertheless,  if  the  b(dt  is  slammed  home 
with  full  force,  sonic  drive-in  can  take  place.  A well  made  .Mauser, 
and  a National  Match  Springfield  were  tested  for  drive-in.  Both 
weapons,  caliber  .yo-'o6  had  a mechanical  liciulsj^cc  of  approximately 
1.940  to  1*941  inches.  A cartridee  was  very  carefully  and  gendy 
loaded  into  each  wxapon  and  a basic  measurement  was  taken.  The 
cartridges  were  then  loaded  with  full  force  from  the  magazine  by 
rapid  manual  operation. 

In  the  Mauser  it  was  found  that  the  cartridge  had  been  driven  in 
.0045  inch,  and  in  the  Springfield  the  cartridge  had  been  driven  in 
-on  inch.  This  actual  drive-in  corresponded  quire  closely  with  the 
apparent  forward  clearance  in  the  two  weapons,  the  Springfield  hav- 
ing over  twice  the  clearance  found  in  the  Alauser. 

The  sum  total  of  mechanical  headspace,  plus  forward  clearance, 
amounts  to  an  operating  or  firing  headspace  quite  beyond  that  in- 
dictated  by  headspace  gauges.  This  is  especially  true  of  rimless  am- 
muiiirion.  Yhe  rim  or  semi-rim  case  cannot  be  driven  in  beyond  the 
headspace  limit,  wlule  the  average  rimless  case  can  be  slammed  for* 
ward  very  appreciably.  A steep  or  abrupt  .shoulder  on  the  rimless 
ease  is  of  decided  advantage  in  this  connection. 

Captain  Johnson  proceeds  to  point  out  that  (he  condition  described 
above  constitute.s  on  open  invicacion  to  variations  in  cartridge  chamber- 
ing and  consequently  to  variations  in  accuracy.  If  the  operator  loads 
each  round  carefully  by  hand,  does  noc  drive  the  cartridge  home  with 
any  force,  gently  closes  and  locks  the  bolt  with  the  lugs  of  the  bolt 
rufebing  the  shoulders  in  the  receiver  as  the  motion  is  completed,  then 
even  wiih  a mechanical  headspace  plus  forward  clearance  of  as  much 
as  .030,  inch,  he  states  that  there  would  probably  be  no  serious  loss 
of  uniformity  between  rounds  ami  no  serious  trouble  with  inaccuracy 
traceable  to  this  cause. 

Suppose,  however,  that  he  loads  one  round  slowly  and  gently,  and 
then  slams  the  next  one  in  with  speed  and  force.  It  is  to  be  expected 
that  he  will  vary  the  seating  of  the  case  and  bullet  in  the  chamber, 
rhe  ignition  and  combustion  may  varv  frorn  a lack  of  uniforn) 
primer  blow,  and  because  the  powder  may  be  more  or  less  piled  up 
, in  the  front  of  the  ease.  This  lack  of  uniformity  would  certainly  be 
expected  to  show  up  in  the  group. 

If  these  factors  can  affect  the  accuracy  of  the  bolt  action  rifle,  they 
may  be  expected  to  show  up  in  much  more  pronounced  form  in 
self-loading  or  semi-automatic  arms  like  the  Garand  Mi,  and  especially 
in  those  made  under  the  .stress  of  wartime  production.  Toferances 
must  be  as  liberal  as  possible,  and  the  forward  clearance  of  the  bole 
maj'  be  expected  to  be  rather  large. 

It  might  be  expected  that  in  such  a gun,  operating  always  under 
the  same  spring  tension,  the  various  rounds  in  the  magazine  would 


1 1 A'J  CH  ICR’s  NoTEIKX>K 


246 

all  be  chambered  with  ccpsd  force,  but  a litdc  reflection  will  reveal 
tl\at  t[\h  is  not  so.  Assume  that  the  iiiasfazine  is  full  and  the  chamber 
is  empty.  The  first  round  is  chambered  partly  by  the  s firing  and 
partly  by  the  operator,  and  is  not  slammed  home  as  it  is  on  sub- 
sequent .sliocs  \^*hen  the  breechblock  opens  at  high  speed  and  rebounds 
with  great  force. 

Moreover,  as  successive  rounds  arc  fired  from  the  magazine,  there 
is  less  and  less  friction  from  the  round  lying  under  the  breechblock, 
because  as  the  magazine  empties,  the  magazine  spring  has  less  and 
less  tension.  'I'hcreforc  the  breechblock  closes  faster  and  harder,  and 
the  final  round  is  chambered  with  maximum  speed  and  force. 

If  \vc  can  get  a combination  of  miniiinim  headspace  and  the  smallest 
possible  forward  clearance,  in  a scjni-automatic  firearm,  the  loss  of 
accuracy  from  the  causes  described  above  would  be  held  to  the 
minimum. 


Headspace  Specificatiofis 

In  the  Carand  Mi  rifle,  the  headspace  is  held  to  umisually  tight 
specifications,  only  two  thousandths  of  an  inch  being  allowed  be- 
tween the  minimum  of  1.942  inche.s  and  the  maximum  of  1.944  inches, 
measured  between  the  face  of  the  locked  bolt  and  the  reference  point 
on  the  shoulder  of  the  chamber.  For  the  M1903  Springfield,  the 
minimum  is  (.940  inches,  and  the  maximum,  1.944  Inches  for  newly 
manufactured  rifles  after  proof  firing.  On  rifles  returned  to  the  arsenal 
for  overhaul,  rhe  maximum  is  1.946  inches.  When  rifles  in  the  hands 
of  troops  are  Inspected,  those  having  a headspace  of  1950  or  over 
arc  returned  for  overhaul. 

After  the  end  of  World  War  II,  there  were  a large  number  of  Model 
H)ij  Fuificlds  sold  to  members  of  the  National  Rifle  Association 
through  the  Director  of  Civilian  Marksmanship.  Before  being  passed 
for  sale,  these  rifles  were  inspected  with  the  1.946  inch  gauge,  and  if 
this  would  not  go  in,  they  were  passed.  If  cliis  gauge  did  go,  they  were 
again  tried  with  the  1.947  gauge,  and  if  this  did  not  go,  they  were 
passed  for  sale.  If,  howe^»er,  the  1.947  g^tige  did  go,  they  were  re- 
jected, and  held  for  overhaul. 

There  is  quite  a technique  necessary  in  testing  the  headspace  of 
any  rifle,  and  particular  care  must  be  used  with  the  1917,  on  account 
of  the  fact  that  it  is  possible  to  exert  a powerful  leverage  on  the 
gauges  through  the  closing  cams. 

The  proper  procedure  is  to  remove  the  firing  mechanism  and  the 
extractor,  and  then  insert  the  guuge,  after  which  the  bolt  is  pushed 
home  and  very  gently  turned  down  toward  the  closed  position.  If 
it  goes  all  the  wav  shut  without  resistance,  the  headspace  is  greater 
chan  the  gauge,  if,  on  the  other  hand,  resistance  is  encountered,  the 
headspace  is  less  than  the  gauge.  Under  no  circumstances  should  any 
force  be  applied  in  closing  the  bolt  on  the  gauge.  As  soon  as  resist- 


Headspace 


247 


ence  is  felt,  scop,  open  the  bolt,  and  push  out  the  gauge  with  a 
cleaning  rod* 

When  the  1917  rifies  were  placed  on  sale  right  after  World  War  II, 
a lot  of  misinformation  about  headspace  in  these  rifles  was  circulated. 
Numbers  of  cx-scrvicc  personnel,  casting  about  for  employment, 
decided  to  capitalize  on  the  knowledge  of  weapons  they  had  gained 
in  the  service,  and  went  into  business  as  gunsinirhs.  Many  of  these 
men,  nnfnrmnarely,  did  not  have  enough  of  the  right  kind  of  ex- 
perience to  make  them  experts  in  this  line,  and  a lot  of  very  bad 
advice  was  given  bv  some  of  them. 

The  purchaser  of  an  Enfield  would  often  take  it  to  a gunsmith 
CO  be  checked,  and  would  be  told  that  it  had  excess  headspace,  and 
was  dangerous  to  slioot.  Some  of  these  owners  wrote  that  informa- 
tion in  to  gun  editors,  and  it  was  printed,  and  soon  the  rumor  grew 
that  it  was  dangerous  to  (ire  a 1917  rifle  purchased  from  the  D.C.M.; 
this  in  spite  of  the  fact  that  these  rifles  had  all  been  in  use  on  and 
off  ever  since  World  War  1,  and  had  an  exceptionally  clean  record. 

I received  a number  of  letters  from  purchasers,  complaining  that 
they  had  received  Enfields  having  headspace  of  over  1.950.  1 per- 
sonally checked  a number  of  these  cases,  and  all  those  checked  had 
headspace  well  within  safe  limits.  Of  course  chat  does  not  prove 
that  there  were  no  1917’s  sold  which  had  excess  headspace;  on  the 
contrary,  I am  confident  that  there  were  some  just  at  first,  before 
the  order  was  issued  that  all  had  to  be  gauged  as  described  above. 
But  the  fact  that  some  self-styled  gunsmith  says  a gun  has  coo  much 
headspace  does  not  necessarily  mean  that  it  docs. 

As  to  gunsmiths,  let  me  say  that  most  uf  them,  no  doubt,  are  good 
sound  operators,  and  know  what  they  are  doing;  I am  not  by  any 
means  condemning  the  whole  tribe,  nor  even  chose  who  made  lionest 
mistakes  at  first;  Jn  gunsniithing,  a$  in  most  other  skilled  trades,  ex- 
perience is  the  best,  and  sometimes  the  only,  satisfactory  teacher. 
Those  who  started  in  a year  or  so  ago  without  adequate  knowledge 
have  p»*obably  either  learned  the  business  or  quit  by  now.  But  right 
after  the  w’ar  there  were  certainly  a lot  of  men  in  the  business  who 
had  not  ycc  had  enough  experience.  Let’s  take  an  actual  example. 
In  1946,  the  owner  of  a .shop  which  w'as  just  starting  into  the  business 
of  converting  F.nficlds  to  spotters  came  In  and  asked  to  have  their 
headspace  gauges  checked,  as  they  had  found  that  all  the  En fields 
they  had  received  for  conversion  were  over  the  1.950  limit,  and  they 
were  afraid  to  convert  them.  But  the  fact  that  they  were  dll  that  was 
made  them  suspicious  of  their  gauge. 

After  the  gauges  were  checked  and  found  to  be  okay,  the  guns 
themselves  were  tried.  First,  the  firing  mechanism  removed,  then 
the  extractor  was  taken  off,  leaving  the  extractor  collar  in  place.  The 
1.950  gauge  was  inserted  and  the  bolt  was  pushed  forward,  and  the 
handle  was  turned  down  very  gently.  Resistance  was  encountered 


Hviuhkr’s  Noithook 


248 

about  halfway  clowns  obvioitsly  the  headspace  was  considerably  less 
chan  the  supposed  1.950.  Tliis  was  repeated  with  a smaller  gauge;  the 
handle  went  almost  all  the  wav  down,  Imt  not  quite,  the  bolt  finally 
closed  on  the  1.943  gauge  in  one  rifle;  the  1.944  next; 

the  1.942  gauge  in  the  following  one,  and  so  on.  All  were  well  within 
limits;  in  face,  better  than  that,  or  nearly  perfect. 

The  shop  foreman  said  thai  as  he  knew  nothing  about  headspace, 

I he  had  asked  two  giinsniirhs  to  sliow  him  how  to  take  it.  1 heir 
system  was  to  insert  the  gauge,  then  close  ilic  holt  as  hard  as  possible, 
i with  the  extractor  and  firing  mcchanbiu  in  place,  and  try  to  pull 
i the  trigger.  If  the  trigger  could  he  pulled,  they  considcreil  that  the 
I gun  had  accepted  the  gauge.  About  like  using  a micrometer  caliper 
by  squeezing  it  down  as  hard  as  pos.sible  with  a Stillson  wrcndi  before 
caUinc  the  reading. 

I III  the  latter  pare  of  1946,  a purctiascr  of  an  Enfield  wrote  in  chat 
his  1917  had  “blown  up”  on  the  fourth  shot,  using  a w'dl  known 
' make  of  factory  loaded  extra  high  power  hunting  cartridge.  This  he 
felt  sure  was  ^uc  to  the  exces,s  headspace  he  had  been  reading  so 
much  ahouc 

I doubted  that  the  rifle  had  “blown  up”  at  all;  the  rroublc  sounded 
more  like  a gas  blow  back  from  a soft  head  or  an  expanded  primer 

Encket,  not  excess  headspace.  I wrote  and  offered  to  give  him  a new 
field  if  he  would  send  me  the  old  one  with  the  cartridge  that 
lud  done  rhe  damage.  1 considered  it  well  vorth  that  much  to  find 
out  about  the  trouble  at  first  hand. 

When  the  gun  came  in,  it  was  in  excellent  shape,  except  that  the 
extractor  was  blown  off  and  the  extractor  collar  bent.  The  offending 
cartridg'e  was  srill  stuck  tightly  in  die  chamber,  and  it  was  a typical 
soft  head,  with  the  primer  pot  ker  expanded  to  about  twice  its  normal 
.size  and  ripped  wide  open  on  one  side,  The  cartridge  was  driven  out, 
the  extractor  collar  and  extractor  replaced,  and  the  rifle  appeared 
as  good  as  new.  The  headspace  was  then  taken,  and  after  all  this 
hullabaloo  it  was  found  to  be  only  1943, 

the  rifle  had  been  “blown  up.”  ' 

On  Nov.  I,  1946,  Al  Barr  and  I roc»k  this  rifle  to  the  range  and 
reamed  the  headspace  out  to  1.955,  fifteen  thousandths  above  the 
normal  minimum,  and  I sat  down  at  the  l>cnch  rest  and  fired  five  1 
shoes  with  Z/2  grain  boat-tail  Mi  ainniunidon,  getting  an  excellent 
group  at  100  yards.  We  then  reamed  it  to  1.960,  and  1 fired  ten  shots,  1 

getting  a considerably  larger  group,  pos.sibly  due  to  the  fact  that  Al  ^ 

was  telling  me  all  the  time  that  I was  taking  a terrible  chance.  After 
rhe.se  ten  shots,  the  headspace  was  again  measured,  and  was  found 
not  to  have  changed  ar  all.  VVe  then  reamed  it  to  J.965,  and  I fired 
five  more  shots.  The  group  was  better,  but  not  as  good  as  the  first 
one;  but  I don't  put  too  much  store  by  rhe  group  sizes,  as  we  had 


Headsfack 


249 

CO  stop  and  chasC  horses  from  behind  the  target,  and  moreover,  we 
had  to  watch  out  for  a couple  of  boys  driving  up  the  cows,  and 
besides  it  was  getting  very  dark  anyhow.  This  last  we  regretted, 
because  wc  wanted  to  go  on  until  we  began  to  get  separated  cases. 
VVe  will  do  that  nest  time. 

Up  CO  this  figure  of  1.965,  or  twenty-five  thousandths  over  the 
normal  minimum,  we  had  gotten  no  reaction  whatever,  and  the  cases 
themselves  showed  only  a very  slight  indication  of  stretching,  and 
were  nowhere  near  a rupture. 

What  docs  this  prove?  Not  very  much,  to  he  sure.  One  lone  test 
doesn't  prove  anything  in  the  gua  business,  and  this  was  not  even 
one  test;  it  was  only  part  of  one.  Why?  Because  headspace  can  occur 
in  several  different  ways,  with  different  effects.  In  this  test  wc  had 
only  one  kind, 

Headspace,  like  that  we  have  when  wc  fire  the  .jRo  A.C.P.  cartridge 
in  the  Luger  pistol  is  really  never  any  greater  than  the  distance  tne 
extractor  lets  the  case  go  away  from  the  face  of  the  bolt.  Without 
the  extractor  holding  it,  the  case  might  go  quite  a way  in,  but  when 
it  i.s  held  by  the  extractor,  it  cannot  go  very  far,  and  this  limits  the 
headspace,  and  holds  the  cartridge  close  enough  so  chat. the  firing 
pin  can  set  off  the  primer.  On  the  other  hand,  if  wc  should  cut  back 
the  locking  shoulders  on  the  bolt,  the  cartridge  might  go  in  snugly 
Jiij  fit  ri^it  up  to  its  shoulder,  and  he  held  clo.se  tnc  bolt  face, 
but  when  the  explosion  occurred,  the  head  of  the  cartridge  would 
not  be  properly  supported,  and  while  the  front  part  of  the  case 
would  be  held  in  place  by  the  pressure,  the  back  part  could  move 
hade  along  with  the  bole,  and  thus  stretch  or  rupture  the  case. 

In  fliis  1917  Enfield,  we  had  headspace  of  the  first  kind.  It  would 
make  little  difference,  in  all  likelihood,  if  wc  Iiad  reamed  the  head- 
space some  distance  further.  It  would  simply  mean  that  there  would 
he  a clearance  in  front  of  the  shoulder  of  the  cartridge.  The  cartridges 
would  not  go  any  further  forward  than  dicj^  already  had,  as  they 
would  be  held  by  the  extractor.  When  the  explosion  came,  the  head 
of  the  cartridge  would  be  supported  by  the  bolt,  and  could  not  move 
back  much;  but  the  shoulder  would  be  expanded  to  fill  the  space 
made  by  the  reaming. 

T doubt  very  much  if  we  would  ever  get  a n:pture  this  way,  no 
matter  bow  much  we  reamed  the  headspace.  We  would  just  move 
the  shoulder  further  and  further  forward. 

On  the  other  hand,  if  wc  had  produced  this  headspace  bv  grinding 
off  the  bolt  lugs,  we  would  have  a condition  where  ruptures  would 
be  more  likely;  if  we  got  one,  it  would  mean  that  the  shooter  would 
open  the  bole  and  only  the  back  part  of  the  shell  would  come  out. 
He  would  be  unable  to  insert  a new  cartridge  until  he  somehow  got 
the  other  piece  out. 


Hatcher’s  Notebook 


25^ 

Velocity  as  a Function  of  Headspace 
Lieut.  Robert  C.  Wyclcoff,  U.S.N.R.  in  an  article  in  The  American 
Riftefnm  for  May,  T947,  reported  some  verv  interesting  tests  clut  he 
made  at  the  Des  Moines  Ordnance  Plant  in  *943  to  determine  the 
cifecc  chat  variations  in  headspace  would  have  on  the  muzzle  velocity 
of  the  bullet. 


Graph  shuwin^  ploneJ  resuirs  of  l.l.  NSVyckolTs  experiments. 


He  selected  a number  of  cartridge  cases  which  all  gauged  1.940 
from  head  to  shoulder,  The  bullets,  caliber  .50  ball,  M2  were  care- 
fvillv  gauged  by  hand  and  selected  to  have  the  same  diameter  and 
overall  length,  and  were  also  selected  as  to  weigh  within  o.t  grain. 

The  cases  were  then  loaded  with  carefullv  hand  weighed  charges 
of  IMR  4676  powder.  The  accuracy  of  the  weighing  was  such  chat 
the  final  balancing  of  the  scales  was  determined  by  the  addition  of 
one  or  two  sticks  of  powder,  of  which  it  requires  about  sixt\"  to 
weigh  one  grain. 

The  bullets  were  all  taken  from  one  machine,  in  order  to  insure 
uniformity  of  ogive.  The  loaded  cartridges  were  held  to  the  same 
overall  length.  In  shore,  every  precaution  was  taken  to  achieve 
uniformity. 

These  cartridges  were  then  fired  in  ten  round  groups  in  a standard 


Headspace 


251 


.30  caliber  velocity  rifle.  The  lustra menral  velocities  were  taken  at 
78  feet  with  a carefully  adjusted  IxRonlonge  chronograph.  After  each 
group  the  chamber  was  reamed  out  a defliiite  measured  amount. 

For  the  first  group,  the  headspace  was  made  as  close  as  possible 
to  1.940  incites,  which  was  also  the  length  of  the  cartridges  from 
head  to  shoulder.  The  bullet  seat  was  made  such  chat  the  bullet 
touched  it  when  the  cartridge  was  seated  home  on  the  shoulder.  TIius 
for  the  first  group,  there  was  no  play  between  the  head  of  the  car- 
tridge and  the  face  of  the  breech. 

After  the  first  group,  the  chamber  was  reamed  a certain  definite 
amount  to  increase  the  headspace,  and  the  next  group  was  fired.  This 
was  continued  until  the  headspace  was  2.005,  more 

than  the  minimum  of  1.940, 

In  order  to  obtain  suflicient  firuig  pin  blow  to  dent  the  primer 
correcrly,  the  cartridges  were  inserted  in  the  chamber  so  that  they 
projected  to  the  rear,  and  had  to  be  pushed  gently  into  the  chamber 
by  the  wed^e  shaped  sliding  breech  block  of  the  Modern  Bond  Uni- 
versal Receiver  which  was  used  for  the  velocity  gun.  As  the  firing 
pin  protrusion  was  ,075,  it  would  have  dented  the  primer  only  .010 
inch  if  the  last  cartridges  had  been  shoved  into  the  chamber  until 
they  seated  on  the  advanced  shoulder  which  had  been  moved  forward 
.065  inch  from  its  first  position. 

The  test  gun  had  no  extractor,  to  hold  the  cartridge  against  the 
face  of  the  bolt,  hence  the  inertia  of  rlie  cartridge  was  depended 
on  to  permit  the  firing  pin  to  dent  the  primer,  but  this  worked  well 
enough  so  that  satisfactory  primer  functioning  was  had  throughout 
the  test. 

Results  Obtained 

The  results  of  this  test  arc  shown  in  the  tabulation  given  below, 
from  which  it  will  be  .seen  that  increased  headspace  does  not  of 
itself  result  in  lower  velocities.  On  the  contrary,  the  velocity  increased 
with  increase  in  headspace  up  to  some  .035  above  the  minimum. 


Tabulated  Results 


Headspace  in  inches 

Velocity  In  feet  per  second  at  78  feet 

1*9395 

*733 

i .9406 

2728 

1.9419 

*755 

1.949J 

2768 

r.9530 

2771 

1.9550 

2767 

1.9650 

2799 

1.9750 

2800 

1.9850 

2742 

1.9950 

2750 

2.0050 

2700 

Hatch f.r's  Xotfrook 


252 

Lieuc.  Wyckoff  commented  that  the  increase  in  velocity  with 
headspace,  followed  by  a decrease  w'as  difficult  to  explain,  but  he 
thought  that  the  increase  might  be  due  to  the  fact  that  as  the  head 
space  is  slowlv  increased  from  the  1.940  value,  the  bullet  has  a space 
to  pass  over  before  the  ogive  and  sides  cncoimter  the  lands  and  begin 
to  be  engraved  by  them.  This  is  right  at  the  time  when  the  bullet  is 
experiencing  its  greatest  acceleration,  and  thus  the  bullet  gains  an 
increasing  amount  of  momcncum  before  the  engraving  and  con- 
sequently, the  retarding  forces  begin  to  act.  This  could  easily  accotmr 
for  the  initial  increase  in  velocity. 

However,  as  the  headspace  is  pushed  to  extremes,  two  things  hap- 
pen that  have  the  opposite  tendency.  First,  there  is  a space  provided 
for  some  of  the  gas  to  escape  around  the  bullet.  Second,  the  density 
of  loading  is  decreased;  in  other  words,  the  powder  has  more  space 
to  c.xpand  into  as  it  scam  u>  burn,  and  this  would  rend  to  slow  dow  n 
(he  initial  rise  in  pressure. 

It  is  quite  interesting  to  note  that  even  with  the  fantastically  ex- 
cessive headspace  used  in  this  rest  gun,  there  w^crc  no  ruptured 
cartridges,  and  the  fired  cases  show'cd  only  very  slight  signs  of 
stretching. 

In  closing  his  report,  Lieut.  Wyckoff  states:  “Many  sportsmen 
are  too  concerned  wnth  excessive  (that  is,  over  the  mythical  limit  set 
by  the  manufacturer  of  the  gun)  headspee.  Increased  headspace, 
even  or  40  thousandths  of  an  inch  over  the  maximum  does  not. 
in  itself,  result  in  lower  velocities.  What  does,  however,  is  erosion  n{ 
the  throat  and  bullet  scat,  and  that  should  be  the  fii*st  thing  to  check 
when  considering  a used  gun,  instead  of  veiling  for  a set  of  head- 
space  gauges.  Even  when  the  bullet  seat  and  throat  are  badly  eroded, 
it  is  possible  to  return  the  sjtm  to  its  original  velocity  hv  cutting  off 
an  inch  or  so  of  the  chaml)cr  end  and  rc-chanibering.“ 


XI 


Block  That  Kick! — 

Some  Observations  on  Recoil 

I was  raised  oti  a farm  a boat  seven  miles  northwest  of  Winchester, 
Va.,  in  a little  valley  between  Hunting  Ridge  and  the  Great  North 
Mounrain.  Around  300  acres  was  in  cleared  land  used  for  crops  or 
pasture,  while  the  remaining  half  square  mile  was  in  timber. 

In  those  days  that  was  indeed  a happy  hunting  ground  for  a small 
boy.  There  may  have  been  game  laws  but  if  so,  1 never  heard  of 
rhcrn»  or  of  a hunting  license  either,  for  chat  matter,  and  the  only 
guns  I ever  saw  or  heard  of  were  the  double-barrel  mu/^lc  loader 
over  the  mantel,  and  later,  when  I was  ten  years  old,  the  new  breech 
loader  that  stood  behind  the  dining  room  door. 

Shells  could  be  had  at  two  cents  each  at  the  village  store  three 
miles  away,  and  at  the  same  store  rabbits  sold  for  ten  cents  each, 
skinned  and  dressed.  I had  seven  rabbit  traps  and  in  the  winter  season 
it  was  a poor  morning  indeed  that  didn’t  find  at  least  one  or  two 
cotcoiicails  waiting  for  me  when  I made  my  rounds. 

There  were  a couple  of  the  horses  that  were  tame  enough  for  me 
to  catch  any  time  I wanted  to,  and  I could  usually  make  rhem  stand 
near  a rail  fence  long  enough  for  me  to  climb  on. 

I was  between  10  and  11  when  via  rabbit,  horse,  and  village  store 
I acquired  some  12  gauge  shells.  I quietly  borrowed  the  doubfe-l)arrcl 
brccch  loader,  proudly  ptic  in  two  of  my  new  shells,  and  fared  forth 
to  see  what  the  day  would  bring  forth.  After  an  hour  or  so  of 
stalking  unknown  game  through  the  woods  back  of  the  hill  pasture 
r came  suddenly  face  to  face  with  what  to  me  was  the  most  terrifying 
of  all  wild  animals,  a large  snake  coiled  up  in  the  branches  of  a wild 
grape  vine  just  waist  high  right  beside  the  path.  Up  to  this  time  I 
had  been  decidedly  afraid  to  fire  that  big  loud  shotgun,  hut  at  the 
sight  of  the  snake  all  misgivings  vanished  and  I let  him  have  both 
barrels  at  the  same  time!  The  results  were  instantaneous,  gratifying 
and  enlightening.  The  snake  was  made  into  a good  imitation  of 
mincemeat.  I was  knocked  head  over  heels  and  landed  flat  on  my 
back.  But  in  spite  of  this  rough  treatment  all  my  fear  nf  shooting  a 
shotgun  vanished,  never  to  return.  I soon  had  a regular  routine  of 
getting  up  before  daylight  and  making  my  way  down  to  the  river 
bottom  rhrmigh  the  early  morning  mist  to  sit  under  the  call  hick  or  v 
tree  and  listen  to  the  dew  dripping  from  the  leaves  until  the  sound 
of  a failing  nut  told  me  that  Mr.  Squirrel  was  up  there  at  work, 
waiting  to  be  bagged  for  breakfast. 

253 


254 


Hatcher’s  Notebook 


All  I knew  when  1 lee  the  snake  have  both  barrels  was  iliac  my 
shoulder  had  gotten  quite  a wallop— ‘i  can  feel  rhe  place  m frosty 
weather  still!’ —but  later  on  I was  told  that  one  barrel  of  a shotgun 
gives  a kick  contiuning  about  a 8 foot  pounds  of  energy,  so  that 
the  two  of  them  tired  at  once  must  have  kicked  me  about  four  times 
as  hard  as  a Springfield  riHe  is  supposed  to  kick. 

Now  it  seems  lo  me  that  there  is  quite  a difference  between 
*‘rccoil”  and  “kick.”  The  shotgun  recoiled,  and  I got  a kick  on  the 
shoulder.  The  recoil  is  mechanical,  while  the  kick,  or  at  least  the 
effect  of  it,  is  mostly  physical  and  psychological.  The  amount  of 
kick  resulting  from  the  recoil  Unve  applied  by  the  gun  is  largely 
dependent  on  the  weight  and  conformation  of  the  shooter,  whether 
he  holds  the  gun  tigluly  or  loosely,  the  presence  or  absence  of  a 
recoil  pad  or  padded  coat,  and  many  other  things.  The  location  and 
shape  of  the  shooters  bones  and  the  texture  of  his  flesh  seem  to  have 
a big  effect  in  some  cases. 

I first  qualified  as  Expert  Rifleman  in  1908  on  the  Navy  range  at 
Annapolis,  using  the  Krag.  There  was  one  chap  shooting  w'itn  us 
who  rnok  the  most  cruel  punishment  from  the  kick.  In  spite  of  the 
fact  that  he  put  a folded  bath  towel  inside  his  shirt  to  act  as  a recoil 
pad,  his  shoulder  was  black,  blue,  and  green  after  each  day’s  shoot- 
ing, while  no  one  eke  on  the  line  used  padding  of  any  kind  and  none 
seemed  to  suffer  from  recoil  to  amount  to  anything. 

Wc  did  our  qualification  firing  with  the  Krag,  but  after  1 was 
picked  to  try  for  the  Camp  Perry  team  I got  acquainted  with  what 
was  then  known  as  the  new  Springfield.  Ic  made  a sharper  report 
chan  the  Krag  and  kicked  worse,  and  gcticrallv  was  looked  on  with 
.suspicion  and  distrust.  Bvit  it  did  shoot  well,  especially  ac  1000  yardi^. 
This  advantage  was  at  least  partly  offset  by  the  pesky  mccal  fouling 
to  w'hich  ic  was  subject.  However,  that  great  rifle  shot,  then  known 
as  Captain,  and  later  as  Ma^r  K.  K.  V.  Casey,  came  down  from 
DuPont  to  show  us  how  to  use  the  Springfield  to  best  advantage  and 
how  to  get  rid  of  metal  fouling.  He  had  with  him  a book  Imosvn 
as  Ordnance  Pamphlet  No.  1925,  Rj4les  for  the  Management  of  the 
Sprins field  Rifle  Caliber  .jo,  Model  of  190;.  He  very  kindly  let  me 
read  it,  and  I saw  several  interesting  items,  among  them  the  following: 
eight  of  rifle  8,69  pounds.  Energy  of  free  recoil  14.98  ft.  pounds.''^ 
I took  this  to  mean  that  the  rifle  tends  to  hit  the  shoulder  with  nearly 
the  same  energy  that  a 15  pound  weight  would  have  if  dropped  a 
foot;  or  a one  pound  weight  if  dropped  14.98  feet. 

I M'ondercd  if  ic  really  did  kick  harder  than  the  Krag,  so  1 found 
the  Krag  book,  and  for  the  old  .45-70  ns  well.  From  these  hooks 
I gleaned  the  following  dam: 


RECOIL  DATA  1 AKtN  FROM  ORDNANCE  PAMPHLETS 


Gun 

Wt  Gun 

Wt.  of  Charge 

tVt.  of  BuUet 

Buiht  Travel 

Muezie  Velocity  Energy  Free  Recoil 

Cfl].  Riilc 

9.}  lb. 

70  gr. 

500  gr. 

32  inches 

1315  f.  s. 

14.4  ft.  lb. 

Cal.  Carbine 

7.9  lb. 

55  gr- 

405  gv. 

22  inches 

Cl 50  i.  s. 

7,5  fr.  lb. 

Krtig  RiHe 

9.1  R7  lb. 

35  TO  4i  gr. 

«o  gr. 

:8.2j  inches 

2000  f.  9. 

10.025  1^' 

Krag  Carbine 

3.075  1^* 

35  to  4a  gr. 

no  gr. 

20.13  inches 

1920  f.  S. 

U.827  t*T.  lb. 

Rifle 

6.69  lb. 

50  gr. 

X50  gr. 

:tA97  inches 

2700  f.  S. 

14.96  ft.  lb. 

Hdow  for  purposes  of  comparison  1 append  the  following  Jara 
reported  by  Aberdeen  Proving  Ground  when  1 was  chief  of  the 
Small  Arms  Division  Tedmical  Suff  in  1950: 


Gun 

Wt.  Gun 

Wt.  of  CibtfTgr 

IP’r.  of  BuJlei 

Bullet  T ravel 

Afuzzle  Velocity 

Energy  Free  Recoil 

Garaitd  .276 

8.525 

}7  pr- 

ti$  gr. 

inches 

1700  f.  s. 

7.25  ft.  lb. 

Garand  .30 

8.83 

$0  gr. 

172  gr. 

21.76  inches 

2653  f.  9. 

15.18  fc.  lb. 

.0?  Rifle 

8.68 

50  gr. 

i/J  gr. 

2 1 .76  inches 

1 

1 

K.55  fr,  lb. 

N 


SoMF  Observations  ok  Recoil 


Ha  ichkr’s  NarRBOOK 


256 

That  b quite  ati  impre^bivc  tabulation,  but  just  what  does  it  mean? 
Whv'  did  shotgun  bowi  me  over  so  fast?  I oegan  to  wonder  just 
how  much  of  an  actual  push  I had  sustained.  So  1 went  at  it  another 
way.  I he  12  jjaugc  siuitgim  ha>i  a lM)rc  .75"  in  «iianicTC(\  \\h:ch  gives 
a cross  section  area  of  .424  scpiarc  inch,  and  die  nvaxinnnn  pressure 
of  ordinal)  shufgun  loads  is  s.iid  u>  be  somewhere  around  10,000 
pounds  per  square  incli.  Thus  for  a brief  instant  the  rearward  push 
by  one  barrel  of  a is  gauge  shotgun  is  some  4240  pounds,  or  over 
two  tons;  and  when  1 bred  both  barrels  at  the  snake  there  were  some 
8400  pounds  or  over  4 tons  pushing  me  back.  Lucky  that  pressure 
didn’t  la.se  iiinrc  chan  a few  ten  thousandch.s  of  a second. 

Lee  us  look  now’  at  the  service  rifle.  T‘hc  bore  ha.s  four  narrow 
lands  with  a diameter  of  .300''  and  four  grooves  three  times  as  wide 
with  2 diameter  of  .308".  The  average  diameter  is  .306"  arul  the  cross 
section  area  is  .074  square  inch.  'The  maximum  pressure  with  the 
'06  ammunition  is  around  50,000  pounds  pec  square  incli,  so  the  gun 
for  a brief  instam  receives  a backward  push  of  37ot>  pounds.  The 
pressure  falls  rapidly  from  its  maximum,  so  that  by  the  time  the 
bullet  leaves  the  muzzle  the  gas  pressure  is  perhaps  7000  [sounds,  and 
the  backward  pressure  on  the  gun  is  still  518  pounds.  It  should  be 
noted  that  the  rate  of  rise  to  the  maxinnini  and  the  rate  of  fall  to 
the  muzzle  pressure,  as  well  as  the  amount  of  the  muzzle  pressure 
itself,  all  vary  with  the  type  of  powder.  With  quick  burning  powder 
the  pressure  of  the  ga.s  when  the  bullet  leaves  less  than  witli  a 
progressive  powder.  A typical  curve,  showing  the  time- pressure 
rdaciun  for  ^06  aiUTnunition  with  150-gram  flat  base  bullet  and  pyro 
powder,  is  shown  on  Page  322.  This  gives  a good  idea  of  the  magni- 
tude of  the  backward  thrust  on  the  gun  and  jasc  how  long  it  lasts. 
Note  chat  After  the  Inti  let  starts  to  move  it  leaves  the  muzzle  in  less 
than  one  thousandth  of  a second.  Recent  tests  (1946)  show  that  from 
the  time  the  firing  pin  actually  touches  the  primer  until  the  bullet 
leaves  the  muzzle  is  .0015  second.  That  agrees  very  well  with  the 
curve,  for  it  takes  an  appreciable  fraction  of  a second  for  the  primer 
to  ignite  and  in  turn  for  it  to  ignite  the  powder  and  then  for  the 
pressure  to  rise  sufficiently  to  start  the  bullet.  It  has  been  estimated 
(Major  J.  C.  Gray,  Ordnance  Engineer,  Research  and  Development 
Service)  that  it  requires  some  4000  pounds  per  square  inch  to  start 
the  bullet  into  motion. 

We  know  from  experience  that  a heavy  gun  kicks  less  than  a 
light  one;  both  tests  and  calculations  show  that  with  a given  bullet 
weight,  powder  charge  and  muzzle  velocity,  rhe  energy  of  free 
recoil  is  inversely  proportional  to  the  weight  of  the  that  is,  a 

gun  weighing  twice  as  much  would  have  half  the  recoil. 

In  1917,  as  a Captain  of  Ordnance  in  charge  of  the  Experimental 
Department  of  Springfield  Armory,  I had  to  provide  facilities  for 


Dynamometer  used  at  5pfm{;ftdd  Armory  for  measuring  recoil.  WliciJ  (csung  a Ijglaw  hflt.  the  fruul  support  shuvnj  was 
aut  used;  the  rifle  was  supported  by  a wire  attached  ai  the  balance.  This  apparatus  gives  a result  slightly  less  than  (he  true  value  of 
the  recoil  energy,  ns  the  attachment  to  the  buu  of  the  gun,  while  it  is  made  as  light  as  possible,  still  adds  some  wet  git  t,  and  to  this 
extent  slows  up  the  recoil.  This  effect  most  be  computed  and  the  results  must  be  corrected  accordingly. 


Hatchkr’s  N<rrFB(K)K 


258 

the  War  Deparcmenc  test  of  machine  guns  and  machine  rifles  held 
there  in  May  of  that  year.  In  conneccion  with  the  tests  we  measured 
the  recoil  of  the  shoulder  rifles  on  a dyeainomecer  constructed  in 
the  Experimental  Department.  It  was  interesting  to  note  that  with 
the  Browning  Automatic  Rifle  weighing  17  pounds  with  loaded 
magazine,  the  measured  recoil  was  just  half  chat  of  an  pound 
Springfield  rifle  tested  at  the  same  rime. 

During  this  period  every  inventor  with  a sctni-aiitomacic  shoulder 
rifle  was  referred  to  Springfield  Armory  for  preliminary  examination 
and  test.  One  claim  frequently  put  forth  by  inventors  was  chat  the 
kick  was  lighter  with  a recoil  action  semiautomatic  because  the 
mechanism  absorbed  the  blow.  This  may  sound  all  right  when  you 
say  it  fast,  but  it  doesn’t  stand  up  under  analysis. 

In  19 1 1 and  thereabouts  when  I was  a Lieutenant  stationed  in 
Florida,  Gving  in  the  edge  of  the  woods  with  aUigators  right  in  my 
back  yard,  I used  to  read  everything  Lieutenant  Whclen  wrote  in 
the  outdoor  magazines,  and  i managed  some  way  ro  buy  mo.st  every 
new  rifle. 

I bought  ammunition  by  the  case,  and  hardly  ever  left  the  house 
wirhoin  a rifle,  and  a .12  target  revolver  as  well  for  plinking  at  water 
moccasins,  shells  along  the  seashore,  or  what  not.  Among  my  rifles 
were  two  Remington  Model  8 Autoloaders,  one  a .25  and  the  ocher 
a .35.  These  rifles  really  did  kick!  And  they  had  long  recoiling 
barrels  that  should  have  absorbed  the  kick  if  any  .such  mechanism 
could.  Ac  the  same  time  I was  shooting  a Belgian  Browning  Auto- 
loading  shotgun  rhat  had  very  much  the  same  kind  of  action  and  a 
noticeably  strong  recoil. 

This  experience  didn’t  agree  very  well  with  the  theory  that  the 
recoil  operated  aucoinaric  action  reduced  die  kick,  so  the  recoil 
dynamometer  was  brought  into  action  and  some  very  plausible  sales 
talk  went  out  the  window. 

Here  is  a quotation  from  my  notebook  of  the  period  191 7-19 191 

“Now  as  to  kick  in  connection  with  recoil  operated  small  arms 
of  automatic  design— 

‘The  silencers  reduce  recoil  a certain  amount,  but  they  arc  not 
in  general  used  to  any  great  extent.  (I'hosc  issued  by  the  Army  for 
the  Springfield  rifle  at  the  rate  of  two  to  each  company  have  been 
withcfrawii  as  it  was  found  that  although  they  do  silence  the  ex- 
plosion, they  cannot  stop  the  crack  of  a bullet  moving  at  supersonic 
velocity.) 

“Some  of  the  recoil  operated  automatic  or  self-1  reading  rifles  arc 
supposed  to  absorb  a parr  of  the  kick  by  reason  of  the  motion  of 
their  recoiling  parts.  In  many  of  those  guns  this  is  not  so.  They  may, 
and  often  do,  kick  much  harder  than  if  the  mechanism  were  locked 
so  that  it  could  not  operate. 

“This  is  easily  understood.  Consider  for  example  a certain  auto- 


Some  Observations  ox  Recoil 


259 

loading  rifle  weighing  about  seven  pounds.  The  more  a rifle  weighs 
the  less  ic  kicks.  But  in  this  autoloader  our  calculations  would  be  in 
error  if  wc  used  seven  pounds  as  the  weight  which  resists  the  recoil, 
for  the  whole  seven  pounds  does  not  stand  up  against  the  kick  of 
the  powder  gas  and  help  absorb  the  shock. 

“The  barrel  and  breech  bolt  are  locked  togerher  and  held  in  place 
in  the  frame  of  the  rifle  by  springs,  so  that  when  the  gun  is  fired 
they  arc  free  co  move  backward  several  inches  independently  of  the 
rest  of  the  gun.  These  recoiling  parts  comprise  only  about  half  the 
weight  of  the  rifle. 

“When  the  gun  is  fired,  the  stock  and  frame  of  the  gun  stand  still 
against  the  shoulder  while  the  barrel  and  bolt  with  their  mere  four 
pounds  of  weight  are  alone  opposing  the  kick  of  the  explosion.  As 
far  as  resistance  to  kick  is  concerned  you  might  almost  as  well  be 
firing  a four  pound  gun. 

“I'hc  lighter  the  parts  that  oppose  tlie  thrust  of  the  explosion,  the 

f [rearer  the  energy  th^  acquii'c.  Titus  in  the  gun  mentioned,  the 
ight  recoiling  pares,  driven  backward  a(  high  speed  inside  the  barrel 
casing  take  up  a heavy  load  of  energy,  then  come  to  a stop  against 
the  inside  of  the  receiver  and  transmit  a large  part  of  this  energy 
to  the  shoulder  of  the  shooter.  The  result  is  tnat  the  gun  has  a 
particularly  vicious  kick.  Shooting  this  rifle  is  what  first  called  our 
attention  co  the  fact  chat  in  a self-loading  gun  of  the  recoiling  barrel 
type  the  whole  weight  of  the  gun  is  not  utiLzed  against  the  recoil 
“Going  into  the  physics  of  this  proposition,  it  was  found  that 
theoretically,  if  the  tw'o  pans  of  the  gun  were  entirely  inelastic,  as 
for  example  if  they  were  made  of  lead  or  putty,  this  effect  would  not 
occur,  for  after  the  two  parts  came  together,  the  recoil  energy  would 
be  reduced  to  what  ic  would  have  been  if  no  independent  motion  of 
the  barrel  had  taken  place.  On  the  ocher  Iwnd,  if  the  parrs  were 
perfectly  clastic,  they  would  act  like  two  ivory  billiard  balls,  and 
ther«  would  be  an  interchange  of  velocity,  so  that  the  recoiling 
barrel  and  bolt  would  stop  and  most  of  the  energy  in  these  parts 
would  be  transmitted  to  the  stock  and  then  co  the  shoulder.  As  the 
steel  gun  parts  have  a high  degree  of  elasticity,  this  is  just  what 
happens. 

“This  reasoning  was  checked  by  firing  well-known  types  of  self- 
loading  and  autoloading  hunting  rifles  in  the  recoil  dynamometer. 

“rhe  guns  were  first  fired  with  semi-automatic  action  and  the 
recoil  was  measured.  Then  the  action  was  blocked  so  that  the  self- 
loading action  could  not  function,  and  the  test  was  repeated.  In  the 
guni>  tried  the  actual  measured  recoil  was  found  to  be  much  less  when 
the  semi-automatic  action  was  out  of  operatic n.“ 

Some  time  before  this  the  Army  had  issued  300  .45  caliber  Savage 
automatic  pistols,  and  when  they  were  withdrawn  and  sold  as  sur- 
plus I bought  one  of  them.  On  firing  this  the  recoil  was  found  co  be 


R«mingtOQ  .45  caliber  automatic  pistol,  clesign^l  by  Mr.  }.  D.  Pedersen,  and  recommended  for  adoption  by  a Navy  Board  at  the 
beginning  of  World  War  I.  The  pistol  was  never  adopted  because  all  available  factories  were  already  being  tooled  up  for  the  M191I. 
This  pistuL  because  o(  its  clever  design,  gives  a recoil  which  is  relatively  light. 


SOMK  OlWtKVATIO.VS  DM  ReCAIIL  26 1 

exccssivc-imicli  worse  than  that  nf  the  M lyii  pi.siol.  I'licn  some 
firing  with  the  Rcmingtnrj  .45,  designed  by  my  close  friend  J.  D. 
Pedersen,  had  revealed  that  this  gun  had  a notably  mild  recoil. 

The  excessive  recoil  of  the  Savage  .45  is  accounted  for  by  the  fact 
that  the  brccch  is  not  locked  and  the  barrel  docs  not  move  back  at 
all  with  the  slide.  I'he  rearward  motion  of  the  slide  is  supposed  to 
be  retarded  by  a cam  arrangement  forcing  it  tu  rotate  the  barrel 
slightly  to  the  right  before  it  can  move  to  the  rear.  The  reaction  of 
the  bullet  against  the  twist  of  the  rifling  is  supposed  to  hold  the 
barrel  to  the  left  and  resist  the  riglit-haiu!  nitaiion  necessary  to  allow 
the  brccch  to  open,  AcrualJy,  however,  the  bullet  has  left  the  barrel 
bef<nc  the  .slide  has  moved  back  far  enough  to  rotate  the  barrel,  so 
the  supposed  locking  cannot  cake  place. 

Going  again  to  inv  >9*9  notes  we  find: 

‘The  same  citing  that  causes  the  nasty  kick  of  sctni-automafics 
actuated  by  barrel  recoil  or  by  straight  blow-back  also  accouius  for 
the  rather  disturbing  recoil  of  the  aiitomacic  pisr<d.  \m  can  easily 
verify  this  by  shooting  one  with  the  slide  l»(ockcd,  and  noticing  how 
docife  jt  is. 

“The  inventor  of  a new  automatic  pistol  chat  one  of  chc  large  anus 
companies  has  just  brought  out  takes  this  fact  into  account  and  con- 
trols the  recoil  verj'  nicely  through  an  ingenious  arrangement. 

“When  the  explosion  occurs,  the  breech  block  is  allowed  to  move 
:i  very  short  distance  to  the  rear,  carrying  the  slide  with  it.  I'he 
brccch  block  then  stops  against  a shoulder  in  the  receiver,  while  the 
slide  continues  to  chc  rear  under  the  niomcntum  imparted  lu  it  during 
the  short  stroke  of  chc  breech  block.  After  it  has  gone  ,wme  distance 
to  the  rear  the  vlidc,  through  a cam  arrangement  again  engages  chc 
brccch  block,  unlocks  k from  the  receiver,  and  carries  it  on  back, 
extracting  and  ejecting  the  empty  shell.  By  controlling  the  length 
of  the  inicial  power  stroke  of  the  breech  block,  the  designer  has 
arranged  so  chat  chc  momentum  tnmsmicced  to  the  moving  parts  is 
just  enough  to  operate  the  mechanism  with  certainty,  but  not  enough 
to  make  the  recoil  disagreeable." 

If  allowing  die  barrel  of  the  gun  to  recoil  indepcndcntlv  of  the 
stock  is  bad,  there  is  one  thing  that  is  worse;  that  is,  to  allow  the 
stock  to  recoil  independently  of  the  barrel.  The  worst  kicking  gun 
chat  I ever  saw  was  one  that  an  inventor  brought  in  to  Springfield 
Armory  somerime  in  1917.  The  breech  block  was  not  locked  to  the 
barrel  at  all.  Instead,  it  was  firmly  fixed  to  the  stock,  while  the  barrel 
was  free  to  slide  forward  against  the  push  of  a spring. 

When  the  gun  was  fired,  the  barrel  moved  forward  and  the  breech 
moved  back  keeping  the  empty  cartridge  with  it.  The  empty  was 
kicked  our  of  the  way,  a new  cartridge  rose  from  the  magarinc,  and 
the  barrel  slammed  back,  chambering  the  cartridge  ready  for  another 


262 


IIatchrr’s  Notrbook 


I 

shot.  I'he  gun  uas  made  up  for  the  Krag  cartridge  in  full  charge. 
^ Ic  functioned  well  enough,  buc  one  shot  was  enough  for  me.  The  kick 
of  a milk  was  mild  by  comparison.  I handed  the  gun  back  to  the 
I inventor,  and  cold  him  that  he  would  have  to  do  any  further  shooting 
that  he  wanted  done.  Ic  that  one  can  gcr  used  to  anything, 

even  the  kick  of  a mule,  for  die  inventor  explained  that  he  was 
“used  to  it,’"  and  proceeded  to  fire  a number  of  additional  shots  with- 
out show'ing  any  unusual  signs  of  discern forr. 


Recoil  in  G^y  Operated  Semiautomatics 

While,  as  has  been  stated  above,  some  recoil  operated  self-loaders 
seem  to  have  the  recoil  increased  by  the  mo\cmcnt  of  the  parts,  this 
does  not  seem  to  be  so  in  gas  operated  guns  like  the  G a rand  Mr  and 
the  Browning  Automatic  Rifle.  Both  these  guns  give  the  impression 
of  a softer  and  lighter  recoil  than  that  given  by  the  M 1903  Spring- 
field. 

With  the  BAR,  the  additional  weight  of  the  gun  would  of  course 
greatly  reduce  the  recoil^  but  this  is  not  so  with  the  Garand,  which 
w'ciffhs  about  the  same  as  the  Springfield.  Nevertheless,  many  users 
of  (bis  gun  remark  about  the  lack  of  unpleasant  kick.  Captain  John  S. 
Rose  of  the  National  Rifle  Association  Technical  Staff  states  that 
when  he  was  instructor  in  the  weapons  section  of  the  Infanrrv  School 
during  World  War  II,  there  was  never  a class  that  went  through  that 
did  not  have  one  or  more  members  who  raised  the  ijucstion  of  whv 
the  Garand  kicked  less  than  the  Springfield.  Strangely  cnougii,  there 
were  also  a few  who  insisted  that  ic  kicked  worse. 


^.^<;aptaiQ_^se  thought  chat  this  inconsistency  miHir  hejiuc.tajbc.... 


ex- 

hers 

fact 

the 


IS  to 
the 
tide, 
ishcs 
bur 
ving 
tion 


i of 
gun 
tc  a 
ter’s 


ans- 


emg 


fact  xfifft-no 'rifle  «ock^‘an  fit  everyone  the  same, 
ccQent  fir  nf  the  stock  with  some  nten  and  the  poor  fie  with  01 
iiiiglu  account  for  the  difference.  This  may  well  be  so,  but  the 
remains  that  the  general  impression  of  the  ,Mi  Garand  is  that 
character  of  the  kick  is  less  unpleasant  ro  the  average  man. 

It  seems  to  me  that  this  reduced  kick  with  gas  operated  guns 
be  expected.  While  the  bullet  is  still  in  Che  barrel,  and  before 
muzzle  blast,  which  accounts  for  a sizeable  percentage  of  the  I 
can  take  place,  a jet  of  gas  enters  the  gas  piston,  and  there  pi 
vigorously  in  two  directions.  Ic  not  only  pushes  the  piston  back, 
it  also  pushed  foru^ard  against  the  inside  of  the  gas  cylinder,  gi 
the  gun  a powerful  forward  impulse  which  is  in  the  opposite  direc 
Co  the  natural  motion  of  recoil. 

Moreover,  rhe  gas  then  goes  on  back  and  out  of  che  rear  eni 
the  gas  cylinder,  acting  like  jet  propulsion,  tending  to  push  the 
forward.  Of  course  the  operating  rod  and  bolt  do  pick  up  qui 
bit  of  rearward  m omentum,  which  has  to  be  stopped  by  the  shoo 
shoulder  eventually;  but  most  of  che  energy  in  these  pirrs  is  ci 
luitted  more  or  less  gradually  through  the  action  of  the  opera 
rod  spring. 


SOMK  OuiJKKVAi'IONS  U.N  RtCOIL 


Upper:  Thompson's  experimetual  recoil  reducer.  Lower:  an  experimeoul 
rmxiel  similar  in  principle  lo  die  l>pe  used  on  ihe  Lewis  airrrafj  machine  gun. 
It  was  tested  at  Springfield  Armory  in  IVOt  Note  the  rod  bayonet  in  the 
original  1905  Model  Rifie. 


Mr.  Garand,  in  discussing  t\m  matter  with  me  in  June,  1947,  stated 
that  the  Mr  rifle  give.s  about  the  .same  mcasiircci  recoil  as  the  Mt903, 
but  that  it  feels  milder  heraiisc  the  rate  uf  applieitifin  is  different. 


Reduchig  the  Kick 

A trip  through  the  Springfield  Annory  Museum  would  convince 
any  close  observer  that  a good  many  people  have  been  crying  for 


HArCHtR’s  NoTtllOOK 


264 

a long  rime  to  do  something  about  making  the  kicking  gun  feel 
less  like  a mnlc.  Fven  before  World  War  I,  muzzle  brakes  and  re- 
coil reducers  were  one  of  rlie  favorite  subjects  for  the  efforts  of 
inventors  and  ex  peri  men  tors.  A number  of  clicse  devices  were  tested 
at  Springfield  Armorv  as  far  back  as  190^,  and  some  of  ihosc  found 
in  the  test  reports  are  shown  in  the  illustrations  which  accompany 
this  discussion. 

All  of  the  devices  rested  worked  on  the  principle  of  intercepting 
a part  of  the  muzzle  blast  after  it  left  the  muzzle  and  turning  it 
sideways  or  backward.  This  is  a promising  idea,  for  over  onc-fourch 
of  the  recoil  vclocitv  of  the  average  high  powered  rifle  is  caused 


An  fxj'erimenjal  fCfoU  reducer  coed  m 5»prmglicld  l>c^o^c  World  War  J 

by  the  rocket-like  thrust  of  the  jet  of  powder  gas  that  rushes  out 
at  high  speed  as  mjou  as  the  bullet  leaves.  If  we  could  suppress  this 
effect  cmircly,  we  would  reduce  the  recoil  vclocitv  of  ilic  gun  bv 
approximately  oiic-fourth,  and  as  the  recoil  vwrrgr  is  proportional 
CO  the  square  of  the  recoil  'velocity,  anything  chat  reduces  the  velocity 
one-fourrh  will  reduce  the  energy  bv  nearly  44  per  cent. 

Of  course  we  could  hardly  expect  to  trap  all  the  gas  and  fake 
away  it.s  reaction  as  it  leaves  the  muzzle,  for  we  have  to  leave  a 
hole  for  the  biillct  to  go  through,  and  a large  pare  of  rlie  gas  is 
sure  to  fallow  the  bullet  out  at  high  vclocitv. 

However,  that  portion  of  the  gas  that  we  do  catch  can  nor  onlv 
be  stopped  from  giving  its  rearward  push,  (lut  can,  in  addition,  be 
made  to  do  work  in  the  opposite  direction  and  give  an  actual  for- 
ward push  on  the  gun.  This  is  accomplished  by  so  shaping  the 
vanes  of  the  muzzle  brake  that  they  will  turn  the  gas  l)ack  toward 
the  rear.  If  the  blades  of  the  muzzle  brake  are  shaped  like  the  blades 
of  an  ideal  turbine,  they  could  in  theory  absorb  up  to  twice  the 
momentiini  0/  the  gases  they  trap.  First  they  could  extract  all  the 
momentum  by  bringing  the  gases  to  a stop,  then  they  could  absorb 
an  equal  ajnounc  of  work  in  giving  the  gases  the  same  momentum  in 


llic  nui2zlc  brake  on  th<  (ierman  high  vcfo(.i(^  7.92mm  anii'Unk  ride. 

n rciirwnrd  direction.  Of  course  no  bnikc  is  chib  efficient  in  ;icrua) 
practice. 

While  iiijuiy  muzzle  brakes  were  tested  in  those  early  days,  none 
were  adopted,  the  reason  l)eing  tlwt  all  of  them,  with  our  exception, 
intensified  to  a disagreeable  degree  the  noise  and  blast  evpcncnced 
by  the  gunner,  and  especLilly  by  those  persons  on  each  side  of  him. 


266 


Hatcher’s  NorKRooK 


However,  with  the  advent  of  the  aircraft  machine  gun  in  World 
War  I,  it  was  found  imporbint  to  reduce  the  recoil  of  machine  guns 
as  much  as  possible,  and  a muzzle  brake  was  adopted  and  used  as 
standard  equipment  on  the  40,000  or  more  Lewis  Aircraft  Machine 
Guns  that  w'e  bought  in  the  war.  As  far  as  1 know,  this  was  the 
first  actual  adoption  by  the  inilitarv  of  a muzzle  brake  on  small 
arms. 

The  first  World  War  also  brought  the  introduction  of  full  auto- 
matic rifles  which  were  light  enough  to  be  fired  from  the  shoulder. 
The  most  popular  and  widely  used  of  these  was  the  Erowning  Auto- 
matic Rifle,  weighing  fifteen  pounds,  and  firing  at  the  rate  nf  about 
550  rounds  per  in  inure  from  a twenty  round  magazine.  When  fired 
full  automatic  from  the  shoulder,  the  muzzle  had  a powerful  tendency 
CO  climb  as  a result  of  the  repeated  impulses.  It  was  soon  found  that 
this  could  be  completely  nullified  by  filing  the  front  upper  edge 
of  the  flash  hider  at  an  angle  so  that  some  of  the  gas  could  escape 
in  an  upward  direction.  This  flash  hider  was  simply  a tube  about 
four  inches  long  and  thrce-fourrhs  of  an  inch  in  diameter  inside,  that 
was  screwed  onto  the  muzzle. 

Only  a very  liede  bevel  was  enough  Co  neutralize  the  climb;  by 
using  more,  the  muzzle  could  be  deflected  downward. 

Th^  Cutts  Compensator 

Shortly  after  the  first  World  War.  Colonel  Richard  M.  Diets  of  the 
U.  S.  Marine  Corps  appeared  at  Springfield  Armory  with  a muzzle 
brake  which  he  callea  the  Cutes  Conipensicor.  1 was  present  at 
several  trials  of  this  device,  which  did  have  some  considerable  effect 
on  the  rccnil.  It  was  sent  to  Ft.  Benning  for  trial  by  the  Infantry 
Board,  but  failed  of  adoption  on  the  service  rifle,  because  of  the  dis- 
agreeable side  and  back  blast.  It  was,  however,  made  standard  on 
the  Thompson  Sub-machine  gun.  On  this  weapon,  the  Cutts  com 
pensator  had  the  slots  cut  in  the  top,  to  neutralize  the  climb.  As  the 
muzzle  pressure  of  the  45  A. CP.  cartridge  used  in  this  gun  is  much 
less  than  that  of  the  service  rifle,  the  blast  was  not  so  noticeable. 

This  device  was  afterwards  applied  to  shotguns  by  the  I/vmaii  Cun- 
sight  Company,  and  is  used  in  connection  with  interchangeable  clK>ke 
Cubes  which  are  screwed  onto  the  front  of  the  compensator.  Like 
the  pistol  or  the  sub-machine  gnu,  tlie  shotgun  has  a low  muzzle 
pressure,  and  the  blast  is  not  very  noticeable.  Various  tests  have 
indicated  that  the  Cutts  Compensator  on  shotguns  may  reduce  the 
recoil  by  from  fifteen  to  thiry'-  per  cent 

A somewhat  similar  looking' device,  with  the  same  object,  is  the 
Weaver  Choke.  This  is  a cylinder  w'hich  screws  onto  the  muzzle  of 
a shotgun,  and  which  is  fitted  at  its  front  end  with  threads  for  inter- 
changeable choke  tubes.  In  the  Cutts  Compensator,  there  are  a number 
of  parallel  slots  on  each  side  of  the  cylinder.  On  the  Weaver  Choke, 


A C.utis  compen<>aior  for  shotguns.  The  slocccd  poriion  reduces  the  teu»il.  Tlic  porciun  ;m  ih«  lefi  ii  a rccnovahle  choke  lohe. 


€ mux 7 If  brake  on  the  Russian  Tokarev  semiaucomacie  tide.  This  vvas  tsidelv  used  in  World  \X  ar  II 


SOMK  ObSHIVVIIONS  Ux\  Recuil 


269 

the  cylinder  simply  has  a number  of  round  holes  bored  in  it.  The 
Weaver  Choke  reduces  recoil  also,  but  not  as  nmch  as  rhe  Cntrs 
Compensator.  The  reduction  claimed  for  the  Weaver  Choke  is 
from  eight  to  thirteen  per  cent. 

The  Tokarev  Semiautomatic 

During  the  second  World  Wir,  one  service  rifle  appeared  with  a 
muzzle  brake  as  regular  equipment,  and  chat  was  the  Russian  Tokarev. 
The  muzzle  brake  on  this  gun  is  quite  effective,  but  it  still  Itas  the 
old  trouble  of  a rather  disagreeable  side  blast. 

The  Johnsofi  Muzde  Brake 

As  soon  as  their  war  work  ended  at  the  clo.;e  of  World  War  II, 
rhe  firm  of  Johnson  Automatics,  of  Providence,  R.  I.,  makers  of  the 


The  Johnson  tmuale  brake.  This  reduce  recoil  from  for  tv  to  fifty  jKfconc  by 
actual  test. 


Johnson  Semiautomatic  Rifle  and  of  the  Johnson  Light  Machine  gun, 
began  putting  out  converted  Cicrnian  Mauser  rifles  as  well  as  Sport- 
ing I vpe  1903  and  1917  conversions.  For  use  on  their  featherweight 
models  Captain  Melvin  M.  Jolinson  developed  a very  efficient  muzzle 
brake,  whidi  weighs  imly  two  tuinccb,  yet  reduces  the  recoil  as 
much  as  forty  per  cent  by  actual  test. 

Captain  Johnson  told  me  that  tests  made  at  the  Massac hu.sects  In- 
stitute of  Technology,  by  having  the  butt  of  the  gun  drive  a steel 
ball  into  a lead  plate,  and  then  calculating  the  recoil  from  measure- 
ments of  the  resulting  indentation,  showed  a forty-one  per  cent 
reduction;  while  tests  made  at  one  of  the  large  arms  factories  using 
a recoil  dynamometer  of  the  pendulum  cv’pe  indicated  a reduction 
of  some  fifty-one  per  cent. 

I have  used  this  device  quite  a bit  nu'sclf,  and  can  state  from 
personal  experience  that  it  docs  decidediv'  reduce  the  recoil.  Captain 
Johnson  stated  that  an  unexpected  dividend  resulting  from  the  use 
of  this  muzzle  brake  is  an  increase  in  accuracy  as  shown  by  his  tests. 
He  attributes  this  to  the  damping  of  barrel  vibrations  by  the  ma.ss  of 
metal  attached  to  the  end  of  rhe  featherweight  barrel.  I have  not  had 


270 


Hatcheh’s  Noteimx>k 


che  opportunity  to  make  any  tests  of  this  feature,  but  it  seems 
reasonable  that  the  muzzle  brake  might  have  this  effect. 

The  Johnson  Muzzle  Brake,  according  to  several  users  with  whom 
I am  well  acquainted,  does  intensify  the  noise  to  a degree  which 
is  quite  noticeable  to  some  persons.  Others  complain  that  ii  kicks  the 
muzzle  down,  and  as  a result,  kicks  die  butt  up  agaime  the  cheek. 
I have  not  been  bothered  by  citlier  of  these  effects;  but  my  imagina- 
tion is  perhaps  not  quire  as  vivid  as  is  that  of  the  average  shooter. 

Recoilless  Cannon 

During  World  War  I,  Commander  Cl  eland  Davis,  U.S.N.,  invented 
a non-recoil  cannon  intended  for  use  on  airplanes,  small  boats,  etc. 

This  consisted  of  a cannon  open  at  both  ends,  and  arranged  with  a 
loading  gate  in  the  middle.  On  che  front  end,  che  powder  charge 
had  the  regular  projectile,  while  on  the  rear  end  it  had  a charge  of 
lead  dust  and  vaseline,  weighing  as  much  as  the  projectile.  On  bring, 
the  projectile  went  forward  and  the  mais  of  lead  and  va<;elinc  went 
backward  at  che  same  speed,  while  the  gno  stood  still  in  the  middle. 
This  gun  had  the  two  .serious  practical  dwidvaniagcb  of  clumsiness, 
and  of  shooting  in  both  directions.  It  was  true  tfiac  the  charge  of 
lead  dust  would  not  carry  to  any  great  distance,  but  it  inhibited  a 
space  directly  behind  the  gun.  As  was  to  be  expected,  this  gun  was 
never  used  to  any  imporcanc  extent. 

The  Bazooka 

During  Wcjrld  War  II,  very  con^derable  use  was  made  of  an 
anci-Lank  weapon  known  as  the  Bazooka,  which  was  a rocket  dis 
charger  operated  by  two  men,  one  of  whom  held  the  weapon  on  his 
shoulder  and  aimed  and  discharged  it,  while  the  other  stood  by  his 
side  to  load.  The  projectile  carried  in  its  nose  a so-called  hollow 
charge,  which  gave  a remarkably  effective  action  against  chick  armor 
place.  This  action  was  based  on  what  was  known  as  the  Monroe 
Effect,  a peculiar  performance  of  high  explosives  under  certain  con- 
ditions, which  w'as  discovered  tWs  way: 

For  setting  off  charges  of  high  explosiv'e  at  a distance  almost  in- 
stantly in  demolition  work  there  is  a kind  of  cord  fuze  known  as 
detonatir^  fuze,  which  consists  of  a lead  tube  containing  a thin 
core  {)(  T.N.T.  When  a detonation  is  started  in  a piece  of  this  fuze, 
it  travels  at  a speed  of  around  7000  meters,  or  nearly  four  miles  in 
a second. 

In  making  tests  on  this  type  of  fuze,  .someone  happened  to  lay 
a piece  down  in  a circle,  and  where  rhe  ends  ioined,  a blasting  cap 
w’as  inserted  and  detonated,  starring  a detonation  in  both  ends  of 
the  piece  of  fuze  at  the  same  time.  Where  the«c  two  waves  met, 
a deep  gash  was  cut  in  the  steel  plate  on  which  the  fuze  was  lying. 
pA-idently  wliere  two  detonation  waves  come  together,  so  that  one 
bucks  the  other,  as  it  were,  something  very  extraordinary  happens. 


Cnicridge,  75mm,  M 310,  foi  73mm  recoilWss  caoooo  M 20.  Not€  pre*engraved  routing  band;  perforations  for  escape  of  gas, 
and  impregnaled  paper  liner  inside  of  case  visible  through  perforations. 


SOMK  OkSFRVATIONJ)  ON  RrCHHi. 


275 

The  forward  end  of  che  Bazooka  projectile  carries  a high  explosive 
charge  hollowed  out  in  front.  Thus  the  detonation  from  all  around 
the  edges  of  the  charge  meets  in  the  center,  and  when  that  happens, 
something  just  has  to  give  way.  To  add  to  the  elTcc  rive  ness,  the  cup 
of  explosive  in  the  front  of  the  bazooka  is  lined  with  a thin  piece  of 
steel,  which  is  blown  into  a cylindrical  slug  bv  the  explosion,  and 
is  rh rn  driven  right  through  anything  that  happens  to  be  in  contact 
with  at  tliC  time.  This  peculiar  device  will  penetrate  the  thick  armor 
<m  any  rank  or  armored  vehicle  used  during  the  war. 

The  velocity  of  the  Bazooka  projectile  was  low;  265  feet  per 
second,  with  a range  of  700  yards.  'I'he  projectile  was  not  spun, 
hut  had  CO  depend  for  .stabilization  on  fins  at  the  rear,  like  those  of 
a bomb.  Consequently  its  accuracy  was  not  great.  The  efficiency 
of  the  projectile  was  low,  because  iivstcad  <n  carrying  only  that 
part  which  was  ciTccnvc  mi  impact,  it  carried  also  the  propelling 
charge,  the  powder  chamber,  aiul  the  stabilizing  fins. 

Colottel  Stud  hr  s Idcn 

One  day  during  the  early  pan  of  World  W ar  11,  Colonel  Rene 
R.  Studkr,  Chief  of  the  Small  Anns  Division,  Research  and  Develop- 
ment Service,  Ordnance,  was  considering  the  shortcomings  of  the 
Bazooka,  and  in  consulting  his  notebook,  he  came  across  some  data 
cm  the  Davis  Non-recoil  Gun  that  he  had  made  vears  ago.  This 
started  a train  of  thought  that  le<l  him  10  make  some  calculations 
that  convinced  him  that  a fnily  recoil  less  cannon  of  very  light 
\s eight  but  great  power  could  be  achieved. 

The  dcvdopnicnc  that  Colonel  Stiidler  envisioned  was  of  such 
magnitude  that  there  seemed  little  possibility  that  it  conlil  be  ac- 
compHshed  in  time  to  be  used  in  rhe  war  rhea  in  firogress;  but 
Colonel  Srudlcr  was  head  of  a rreineiidous  and  highly  efficient  .small 
arms  development  organr/atioii,  so  he  endted  in  a few  selected  assis- 
tants and  explained  what  he  w*anted  done. 

The  result  was  the  design,  test,  and  actual  production  In  time  for 
vitally  important  use  in  rhe  war  of  one  of  the  most  fantastic  weapons 
ever  conceived;  a full  sized  cannon  that  could  be  fired  fr<»ni  the 
shoulder  of  one  man,  and  that  could  throw  a ilircc  pound  high  ex- 
plosive shell  with  a muzzle  velocity  of  i2tK>  feet  per  second  to  a 
range  nf  over  4SKX1  yards  with  an  accuracy  comparable  to  that  of 
the  Ml  rifle. 

This  is  the  57  millimeter  recoillcss  cannon.  In  addition  there  is 
also  the  7^  mm  fired  from  an  ordinary  machine  gun  tripod,  and 
giving  its  fourteen  pound  shell  a muzzle  velocity  of  about  1000  feet 
per  second  for  a range  of  some  four  miles. 

In  an  article  in  The  Amerlcmi  Rifteimn  for  September,  1945, 
Lieutenant  Colonel  B.  B.  Abrams  of  the  War  Department  General 
Staff  says:  “Rccoilless  rifles  were  used  against  the  Germans  early  in 


K> 

Ov 


The  7^mm  recoilUss  cannon  M2ll  on  » machine  gun  irip4Kl«  with  lighting  equipment  and  a conip!c;c  f.'>und  of 

ammunition. 


Hatchfr's  Xotkwk)^ 


Some  Obsekvations  on  Recoil 


277 

the  spring  of  1945,  and  were  especially  well  adapted  for  use  by  air- 
borne units  because  of  cheir  light  weight  :md  simplicity  of  operation. 
During  one  airborne  operation  on  the  Rhine  River  In  March.  1945, 
two  rounds  from  a 750101  recoil  less  rillc  knocked  out  two  Ciennan 
nnd  two  ;<)mni  gum  concealed  in  .1  building.  Roth  XK's  were 
<lcsrroycd  and  about  one  btnulrcd  Cjcniums  captured."' 

In  tlic  same  article.  Colonel  Abrams  stares  further;  “Jn  Che  Pacific 
War  the  recoil  less  guns  have  been  of  inestimable  value,  particuiarlv 
in  blasting  the  Japanese  from  caves  and  Inuikcrs,  and  in  bringing  fire 
to  bear  against  the  enemy  from  sites  where  it  would  be  impossible  to 
transport  and  emplace  the  conventional  artillery. 

“I'hc  57mm  gun  weighs  about  55  pounds  complete  with  accessories 


OLIVE  DftAB 
(MARKING  IN  YELLOW) 


APPROX 


Curtfklgc.  iCLA-T,  <Hi^  lixplosivc  AnuTiink),  T22.  S7mm  Rifle,  Noic 
|>rvva>< raved  rotating  band,  perforated  cartridge  rase,  and  headspacing  band  at 
mouth  ot  case, 

I and  can  be  carried  by  one  man  for  short  distances  or  by  t\so  men 
over  long  distances,  'I'hc  75mm  gun  weights  about  166  pounds  com- 
plete with  mount  and  sighting  instrument.s,  and  is  carried  by  five  men. 
Compare  these  weights  witli  the  weight  of  the  smallest  type  of  con- 
ventional Held  artillery,  weighing  over  a ton.  in  use  bv  the  United 
States  Army. 

“Both  types  of  recoillcss  rifles  arc  usually  fired  by  a two-man 
team  consisting  of  a gunner,  who  actually  fires  the  giin,  and  an  assis- 
tant gunner  vvho  loads  the  ammunition.  However,  it  is  possible  for 
one  man  to  operate  the  57mm  gun  by  liimsclf.  The  gunner  alines 
the.  sights  and  fires  the  piece.  The  assistant  gtmner  opens  the  breech 
and  inserts  the  projectile,  and  removes  the  empty  case  after  firing. 

“The  doughboys  claim  that  the  recoil  less  rifles  are  as  accurate  as 
the  Ml  Rifle,  and  can  easily  liic  a lank  at  ranges  of  from  60  to  1000 
yards.  They  also  advise  against  using  the  57mm  rifle  for  hunting 
any  wild  game  other  dian  Japs?  A hunter  armed  with  this  weapon 
has  no  difficulty  in  hitring  his  target,  but  there  is  nothing  left  of 
the  target  to  take  home!” 

Ho'w  It  Is  Do7te 

The  fundamental  idea  back  of  this  deveh^pment  «as  to  provide 


Hatcjier’s  X<m:iKX)K 


27S 

several  openings  in  the  breech  of  the  gun,  and  to  allow  some  of 
the  gas  to  squirt  out- of  these  openings,  after  the  manner  of  the  jets 
of  a jet  propelled  plane.  These  jets  will,  of  course,  tend  to  drive  the 
gun  forward  at  the  same  time  that  the  usual  recoil  is  trying  to  drive 
It  back. 

Of  course  this  idea  took  a tremendous  ajiiount  of  working  out. 
The  chamber  of  the  gun  was  made  much  larger  than  the  cartridge 
case.  I'he  case  itself  had  its  walls  perforated  with  hundreds  of  small 
holes,  to  let  the  gas  out  inK>  the  chamber.  The  breech  block  had 
several  orifices  or  venturi  tubes  to  form  the  gas  jets  and  direct  them 
not  only  to  the  rear,  to  neutralize  the  recoil,  but  also  at  a slight  angle 
to  counteract  the  turning  effect  ox  reaction  from  the  rifling,  which 
tends  to  cause  the  gun  barrel  to  rotate  as  well  as  to  recoil. 

Because  xhc  resistance  of  forcing  the  copper  rotating  band  of  the 
projectile  into  the  rifling  is  high,  and  is  quite  variable  even  when 
the  greatest  care  is  taken  in  making  the  bands,  it  was  decided  to 
make  grooves  for  the  rifling  beforehand;  or  in  other  words,  to  pre- 
engxave  the  rotating  bai«l  of  die  projectile.  That  means  that  the 
loader  has  to  cum  the  projectile  sLghtly  when  he  inserts  it,  until 
he  feels  the  rifling  enter  the  grooves  already  cut  for  it. 

In  order  to  cover  up  the  holes  in  the  walls  of  the  cartridge  case, 
there  is  a liner  inside  of  the  case,  made  of  impregnated  paper  which 
will  blow  through  the  holes  just  after  the  pressure  has  risen  enough 
to  start  the  projectile  from  the  mouth  of  the  case. 

Obviously,  the  jets  of  gas  escaping  to  the  rear  of  the  rifle  re- 
sult in  a danger  space  behind  it,  which  must  be  kept  clear  of 
perbonnel.  The  danger  zone  is  a triangular  space  about  fifty  feet  to 
the  rear  of  the  breech  and  extending  to  some  twenty-five  feet  on 
each  side.  The  blast  will  throw  up  particles  for  a distance  of  about 
100  feet  behind  the  gun. 

It  has  been  found  that  as  the  venturis  in  the  breech  block  wear 
from  gas  cutting,  the  recoil  becomes  ovcr-compensatcd,  and  the  gun 
will  tend  CO  move  forward  on  discharge.  When  this  becomes  apparent, 
replaceable  elements  are  used  to  bring  the  venturis  back  to  their 
proper  size. 

Colonel  Studlcr,  who  fathered  the  idea,  and  who,  utilizing  all  the 
resources  of  his  organization,  drove  it  through  to  a successful  con- 
clusion, modestly  refuses  to  claim  any  large  share  of  the  credit.  He 
says  chat  it  was  the  w’ork  of  the  organization,  not  of  any  one  man, 
and  in  Army  Ordnance  for  September-October,  1945.  he  gives  credit 
to  a number  of  persons  whose  efforts  were  jointly  responsible  for 
the  results  obtained.  In  the  same  issue  of  Artny  Ordnance^  General 
Barnes,  former  i\,ssiscani  Chieff  of  Ordnance,  called  the  recoillcss  rifie 
“One  of  the  Ordnance  Department’s  more  spectacular  pieces  of  re- 
search . . . outstanding  as  a development,  placing  weapons  of  un- 
precedented power  in  the  hands  of  the  individual  soldier  . . . 


XII 

The  Theory  of  Recoil 

II  IS  obviou:>  that  the  weight  of  tlic  «fun  an  important  factor 
in  determining  how  much  it  wil!  kick.  If  the  gun  and  bullet 
weighed  the  same,  the  gun  would  come  back  as  fast  as  the  bullet 
went  forward,  so  that  breech  and  muzzle  would  be  about  equally 
dangerous. 

In  practice,  however,  guns  arc  always  much  heavier  than  the  bullets 
they  fire.  The  Springfield  rifle  is  some  four  hundred  times  as  heavy 
as  its  bullets,  and  over  three  hundred  times  as  heavy  as  the  combined 
weights  of  bullet  and  powder  charge,  so  tliat  the  recoil  energy  is  in 
the  order  of  one  three  hundredth  of  the  combined  energy  of  bullet 
and  products  of  combustion  as  they  leave  the  muzzle. 

We  can  say,  therefore,  the  heavier  the  gun,  the  less  the  recoil,  and 
conven^,  tf^e  heavier  the  bullet  and  powder  enc^g>^  the  greater  the 
recoil.  Tnus,  anything  that  adds  weight  to  the  gun,  or  in  effect 
adds  such  weight,  is  a help  in  preventing  kick. 

When  the  gun  is  held  tighdy  against  the  shoulder,  parr  of  the 
weight  of  the  shooter’s  body  is  in  effect  added  to  the  weight  of  the 
gun,  and  the  result  is  somewhat  like  chat  of  using  a licavier  gun.  The 
recoil  has  more  mass  opposed  to  it,  so  never  does  develop  to  as  great 
an  extent  as  it  would  if  the  rifle  were  free. 

In  measuring  or  calculating  recoil,  it  is  usual  to  obtain  what  is 
termed  the  *‘Frec  Recoil;”  that  is,  the  recoil  velocity  or  recoil  energy 
developed  by  the  gun  alone,  with  no  other  mass  added  to  it  that  will 
help  oppose  its  rearward  acceleration.  In  practice  some  kind  of  addi- 
tional weight  or  resistance  almost  always  comes  into  play,  hence  we 
seldom  encounter  as  violent  a kick  as  the  free  recoil  would  give,  but 
we  still  find  it  convenient  to  use  this  figure  as  a measure  of  the  kick- 
ing potentialities  of  one  gun  as  compared  to  another. 

In  the  course  of  an  cxccllcm  dheusskm  of  recoil,  the  hru'ish  Text- 
book of  Small  Anns,  lyoi;  edition,  states. 

“The  physiological  sensation  produced  by  the  recoil  is  generally 
termed  ilie  ‘kick.’  It  is  probable  that  the  kick  is  intensified  by  the 
rapidit)^  of  the  first  rise  in  velocity,  which  with  the  Lee-Mctford  rifle 
is  attained  in  about  .ooexS  seconds.  The  .shorter  the  time  in  which 
this  maximum  is  reached,  and  the  greater  the  velocity,  the  more 
violent  the  kick;  from  this  it  follows  that  the  kick,  tliough  no 
doubt  depending  chiefly  on  the  cneigv  of  recoil,  cannot  be  said  to 
be  strictly  proportional  to  the  latter  alone  in  various  arms  and  with 
different  powders  . . . 


»79 


28o 


Ha'iciier’s  Xotisbook 


‘^The  kick  is  reduced  by  pressing  the  rifle  firmly  against  the 
shoulder,  and  by  letting  the  latter  come  back  freely  wiien  tlic  rifle 
recoils,  for  then  part  of  the  weight  of  the  firer’s  body  Is  added  to 
that  of  the  rifle,  therefore,  the  velocity  of  the  latter  is  reduced,  and 
the  kick  partakes  more  of  the  nature  of  a push.  If  the  rifle  is  held 
very  loosely,  or  is  fired  when  snap  shooting,  before  it  touches  the 
shoulder,  the  kick  becomes  a blow,  wliicli  is  more  damaging  to  the 
firer’s  shoulder  than  the  kick  from  the  rifle  when  it  is  properly  held. 

‘‘A  sportsman  feds  (he  kick  of  his  weapon  much  more  when 
firing  at  a target  than  when  firing  at  game,  for  in  the  latter  case 
his  actenrioti  is  fixed  on  his  quarry,  and  he  perfoniis  the  required 
movements  automatically  without  bracing  his  body  to  resist  the 
recoil. 


“The  recoil  energy  of  the  Lee -Enfield  rifle  (12.75  pounds) 
is  well  below  the  maximum  cnci^  of  recoil  advisable  for  a military 
rifle,  which  should  not  exceed  15  foot  pounds. 

*'Thc  recoil  of  a 1:  bore  shotgun  is  double  this  .amouiu,  aiui  al- 
though not  excessive  in  the  field,  is  very  apparem  when  firing  at  a 
target, 

“Tlic  following  fable,  giving  the  particulars  of  the  recoil  of  a 12 
bore  shotgun  is  taken  from  an  article  by  f^pcain  journce  in  MC'- 
morial  des  Foudres  at  SalpitreSy  Volume  lit.  'I'hc  gun  was  suspended 
by  long  strings,  and  the  velocity  of  recoil  w*as  ascertained  by  attach- 
ing to  the  gun  a tvining  fork  whose  arm  traced  a wavy  line  on  a 
plate  placed  parallel  to  the  direction  in  which  rhe  weapon  recoiled. 

the  time  occupied  by  each  vibration  of  the  timing  fork  is 
constant,  and  is  known  beforehand,  the  velocity  of  recoil  at  any  point 
can  be  calculated  by  dividing  the  distance  between  vibrations  at 
chat  poinr  by  the  time  occupied  by  a vibration.” 


Recoil  of  a u Bore  Shotgun 


Weif^ht 

Muzzle 

1 

Velocity 

Energy 

Of  the 

\*clocrcy 

of 

of 

Of  rhe 

Of  the 

Of  Che 

smokeJess 

of  the 

recoil 

m:«il 

gun 

shot 

wads 

pnwder 

shot 

lb.  oz. 

oz. 

gfs. 

f.  s. 

f.  s. 

ft.  lb. 

7 i^A 

*•17 

4iM 

49-4 

1 fdi  I 

16.8  1 

^*4 

The  British  Textbook  of  Small  ArmSy  1929  edition,  stated: 

“As  regards  the  sensation  of  recoil,  it  seems  well  established  chat 
the  actual  velocity  of  recoil  is  a very  great  factor.  In  shotguns 
weighing  six  to  seven  pounds,  fifteen  f.s.  has  been  long  esrablishcd 
as  a nuixiiiiuin  above  which  gun-headache  is  sure  to  ensue.  But  with 
an  elephant  rifle  weighing  perhaps  fifteen  pounds,  such  a velocity  is 
unbearable  for  more  chan  one  or  two  shots.” 


The  Theory  ov  Rtx:oiL 


281 


Ic  will  be  noted  chat  tu  this  example  the  recoil  velocity  rather  than 
the  energy  has  been  given;  a seven  pound  gun  with  a recoil  velocity 
of  fifteen  feet  per  second  would  have  24.16  foot  pounds  of  energy, 
while  a fifteen  pound  elephant  rifle  would  have  52.47  foot  pounds. 

Measurement  of  Recoil 

Figures  for  actual  measured  recoil  velocity  for  several  guns  arc 
given  in  the  1929  Textbook  of  Stnall  Anns,  referred  to  above.  These 
were  obtained  by  attaching  the  gun  rigidly  to  a ballistic  pendulum 
and  firing  it.  From  the  swing  of  the  penduhim  the  recoil  velocity 
was  then  caicniared.  It  should  be  noted  that  this  method  does  not 
measure  the  free  recoil  of  the  weapon.  Rather  it  measures  the  greatly 
reduced  recoil  of  what  is  in  effect  a vci^’-  heavy  gun:  that  is,  the  actual 
gun  and  the  pendulum  bob  attached  rigidly  to  it.  From  the  relative- 
ly small  recoil  thus  obtained,  calculations  arc  made  to  find  oik  what 
the  results  would  have  been  had  only  the  gun  by  itself  been  used. 

This  method  gives  a figure  based  on  vtomemuniy  consist  ing  of  the 
weight  of  the  gun  in  pounds  times  the  recoil  velocity  in  foot  seconds. 
Dividing  this  by  the  weight  of  the  gun  gives  the  recoil  velocity  of 
the  gun.  Squaring  this  velocity  and  inultiplymg  it  by  one-hal/  the 
mass  of  the  gun,  will  give  the  recoil  energy.  Tlic  order  of  magnitude 
of  results  obtained  by  this  method  can  be  seen  from  the  following 
table,  taken  from  the  same  work: 


Measured 

recoil  Weight  Recoil  Recoil 
Gun  momcntuin  of  gun  velocity  ciiei^y 

Ihs.xf.s.  lbs.  f.s.  ft.  lbs. 


S.  M.  I ,.  E.  Rifle  with  .J03  cig.  Mk.  VII  .. 

Experimental  .50  caliber  rifle  

Same  with  muzzle  brake  

12  gauge  shogun  


9.0 

11.0 

285 

rK.n 

16.0 

70.0 

212 

20.0 

55,0 

V7I 

fi-5 

15.0 

22.8 

Reported  Vahtes  of  Shotgun  Recoil 

Some  years  ago  it  was  the  practice  for  powder  and  ammunition 
coinpaniess  to  publish  quite  a bit  more  inrormation  than  they  are 
willing  to  turn  loose  at  present.  At  that  time  duPont  issued  a leaflet 
giving  the  following  information  on  the  relation  of  the  recoil  of  a 
shotgun  to  the  weight  of  the  gun,  the  size  of  the  charge,  the  muzzle 
velocity,  and  several  other  factors: 


282  Hatcher’s  Notfrook 


Mu22le  Velocity  and  Reco3  for  Weight  of  Oun  and  Load 


Weight  of  gya 
lb$. 

Powder,  c<)uivaUnt 
(IraiKN 

Shot 

ozs. 

Mu  eric  velocity 
f.s. 

Recoil 

fc.lbs. 

6 

1% 

**95 

24,6 

6% 

3 

iH 

*255 

25.B 

3« 

*5*3 

27«5 

3W 

»37> 

28.Q 

3 

r2  lo 

26.8 

y 

/ 

t*A 

1428 

)0.0 

7 

344 

t% 

I26q 

2B.3 

3fi 

1^ 

*4*7 

5M 

7‘/, 

5!4 

1*; 

*327 

3245 

1% 

*4*7 

30.3 

7'/: 

344 

}% 

*527 

30.0 

7 >4 

34i 

1% 

14*7 

29.4 

:‘A  . 

3H 

lV4 

15*4 

31.0 

» 

m 

i*A 

•443 

32.6 

ay. 

i'/i 

1% 

•443 

3*‘7 

y-i 

1% 

•445 

30.8 

sy. 

iV> 

*443 

28.9 

Methods  of  Measurement  Compared 

The  mosc  convincing  method  of  measurement  of  free  recoil  is 
that  which  measures  the  quantity  directly,  and  requires  no  secondary 
calculations  ro  obtain  the  desired  result.  This  Is  best  done  by  hanging 
the  gun  alone  by  parallel  wires  so  that  it  can  move  frcelv  to  rhe  rear 
when  it  is  fired.  *lhc  velocity  of  recoil  is  then  measured  by  tuning 
fork  or  high  speed  camera. 

Various  recoil  dynamometers  are  in  use  which  purport  to  measure 
the  free  recoil  by  recording  the  compression  of  a spring,  or  the 
indentation  made  in  a block  of  lead  by  a steel  ball  attached  to  the 
butt  of  the  gun,  etc.  These  arc  useful  for  quick  comparative  measure 
ments,  but  in  general  they  do  not  give  the  free  recoil,  but  rather  the 
recoil  as  modified  by  the  %vcight  of  certain  attachments  and  the  re- 
sistance of  the  spring  or  lead  block. 

The  method  of  measuring  shotgun  recoil  which  is  standard  in  the 
industry  at  present  is  to  fire  the  shell  under  tesr  in  a fifty  pound 
gun  hung  by  parallel  wires  so  that  it  swings  on  a five  foot  arc  as 
It  moves  ro  the  rear.  Tlie  results  obtained  are  used  as  a basis  for 
calculating  to  find  what  the  rccofl  would  be  with  any  given  weight 
of  gun, 

Calculation  of  Recoil 

When  a gun,  such  as  the  Model  Springfield  rifle  is  fired,  the 
pi-essure  of  the  pow'dcr  gas  pushes  on  the  base  of  the  bullet,  tending 
to  drive  the  bullet  forward,  and  exactly  the  same  push  is  exerted  on 
the  rifle,  rending  to  drive  it  back. 

It  is  true  that  the  rear  end  of  the  cartridge  case  is  larger  than  the 
base  of  the  bullet,  so  at  first  it  might  seem  that  the  rearward  pressure 


The  Theory  ov  Recoil 


on  the  gun  would  be  greater  than  the  forward  pressure  on  the  bullet. 
However,  the  powder  pressure  on  che  inside  of  the  body,  shoulder 
and  neck  of  the  case  gives  a forward  push  on  the  sloping  walls  of 
the  cartridge  case  body  and  neck  which  balances  all  che  rearward 
pressure  except  that  on  a circle  the  diameter  of  the  bore.  So  when 
the  gun  is  fired  we  have  at  any  insunt  a total  load  of  a certain  num- 
ber of  pounds  pushing  the  bullet  forward,  and  the  same  number  of 
pounds  pushing  che  gun  back.  This  is  the  reasoning  behind  the  state- 
ment already  made  that  if  the  gun  weighed  just  the  same  as  the 
bullet.  It  would  come  back  just  as  fast  as  the  bullet  goes  forward, 
However,  the  gun  weighs  several  hundred  rimes  as  much  as  the  bullet, 
and  powder  cliargc  combined;  hence,  the  bullet  and  powder  gases 
go  forward  many  hundred  times  as  fast  as  the  gun  comes  back. 

Resistance  by  any  object  to  morion  when  a force  is  applied  depends 
on  the  mass  oj  the  object,  which  is  simply  its  weight  divided  by  che 
acceleration  of  gravity.  Gravity  accetcraces  a falling  body  feet 
per  second  for  every  second  it  acts;  hence,  the  acceleration  of  gravity 
is  j:.i6  feet  per  second,  per  second.  Not  just  “feet  per  second,’*  but 
“feet  per  second  per  second.** 

We  can  call  this  simply  ji.id  if  wc  arc  careful  always  to  stick  to 
the  units  of  feet,  seconds,  and  pounds.  Accordingly,  If  the  bullet 
and  powder  weights  arc  given  m grains,  we  must  be  careful  to  bring 
them  to  pounds  by  dividing  the  weight  in  grains  by  the  number  of 
grains  in  a pound  avoirdupois,  which  is  7,000. 

Principles  of  Physics  Involved  in  Recoil  Calcuiathv 

Before  going  further,  let  us  designate  some  letters  to  represent 
the  various  quantities  wc  will  encounter  on  our  calculaii<)ns  regarding 
recoil,  as  follows: 

F=Force  exerted. 
g= Acceleration  of  gravity,  32.16. 
a = Acceleration  due  to  powder  pressure. 
t=Timc  in  seconds  during  which  presburc  acts. 

W?=Weight  of  gun  in  pounds. 

W 

M^Mass  of  the  enn— — —t- 

^ 32.16 


w=Weiffhc  of  the  bullet  in  pounds  =—  . : — 

® wt.  in  grains 

w 

m=Mass  of  the  bu11et=  — — 

32.16 

c— Weiglic  of  powder  charge  in  pounds. 
z=We!glit  of  wads  in  pounds. 
v=>Mu22lc  velocicv  of  bullet  in  feet  per  second. 
V=Recoil  velocity  of  gun  in  feet  per  second. 
E=Muzzle  energy  of  bullet  in  foot  pounds. 

R — Recoil  energy  of  gun  in  foot  pounds. 


Hatcher’s  Notebook. 


284 

The  basic  principles  of  physics  involved  in  recoil  calculations  are 
based  on  Newton’s  third  law  of  iiwtion,  wliich  is: 

Third  Lav):  To  every  action  there  is  ahvays  .77;  eqtial  reacHon^ 
or  in  other  v:ords,  rf  a force  acts  to  chany^e  the  stsre  of  motion 
of  a body,  the  body  c^ers  a resistance  equal  and  directly  op~ 
posit e to  the  force. 

The  basic  eauations  involved  arc  as  follows: 

Whe7i  a hody  'xhicb  is  free  to  move  is  acted  on  by  a jorcc  F, 
the  resulting  acceleration  a is  equal  to  the  force  divided  by  the 

F 

mass  m of  the  body  or  a= — 

* m 

The  velocity  v which  results  when  an  acceleration  a operates  for 
a time  t js  equal  to  the  acceleration  mulciplied  by  the  interval  during 
which  the  acceleration  operates.  Starea  in  equations,  v=at,  and 

F Ft  . - 

since  a*s — , v ^ , and  vm  = Ft. 

m ’ m 

w 

'riic  quantity  vm,  or — v,  which  is  die  velocity  of  a body  rimes 

g 

its  mass,  is  called  momentum,  and  is  equivalent  to  that  constant  force 
which  would  bring  the  moving  body  to  rest  in  one  second. 

The  Three  Elements  of  Recoil 

The  production  of  recoil  in  a gun  is  due  to  three  separate  causes. 

The  first  is  the  reaction  which  accompanies  the  acceleration  of  the 
bullet  from  a state  of  rest  to  the  velocity  it  possesses  when  it  leaves 
the  gun,  that  is,  to  its  mu^^le  vclocin*. 

The  second  is  the  reaction  which  accompanies  the  acceleration  of 
the  powder  charge  in  the  form  of  gas  to  a velocity  io  the  order  of 
half  the  muzzle  velocity  of  the  bullet.  When  the  bullet  leaves  the 
muzzle,  the  gas  occupies  the  whole  interior  of  the  chamber  and  bore. 
Parc  of  the  gas  has  moved  as  far  as  the  bullet  has,  and  has  a velocity 
equal  to  the  bullet’s  muzzle  velocitv.  Part  of  the  gas  is  in  the  chamber, 
and  has  not  moved  forward  at  alL  The  average  is  slightly  less  than 
half  the  muzzle  velocity  because  the  chamber  is  larger  chan  the  bore, 
and  the  gas  still  in  the  chamber  and  w^hich  has  not  moved  forward 
is  slightly  higher  in  percentage  chan  riiat  w'hich  has  followed  the 
bullet  all  the  way.  Hence  the  average  forward  velocitv  possessed  by 
the  powder  gas  at  the  instant  of  bullet  exit  is  slightly  less  than  half 
the  muzzle  velocity  of  the  bullet. 

The  third  is  the  reaction  due  to  the  muzzle  blast  which  occurs 
when  the  bullet  leaves  and  releases  the  gas,  which  rushes  out  and 
gives  the  same  kind  of  reaction  or  push  that  propels  a rocket  or  a jet 
plane. 

Let  us  consider  for  the  moment  the  first  element  only,  which  is 


Tiif.  Thfory  of  RFa»ii.  285 

thi»c  pan  of  the  recoil  that  is  caused  by  the  reaction  of  accelerating 
the  bullet  to  its  muzzle  velocity. 

The  forward  pusli  on  the  base  of  the  bullet  in  pounds  is  the  same 
as  the  rearw'ard  push  on  the  gun  in  pounds.  It  acts  on  the  bullet 
from  the  time  it  starts  its  mouon  until  it  leaves  the  muzzle,  and  it 
acts  on  the  gun  for  exactly  the  same  length  of  time.  At  the  instant 
the  bullet  leaves  the  muz/Jc,  the  rearward  motion  of  the  gun  in  feet 
per  second,  rimes  its  mass,  is  the  same  in  quantity  as  the  muzzle 
velocity  of  the  bullet  times  the  bullet's  mass.  1‘hat  is  to  say,  the 
rearward  mojiientum  of  the  gun  due  to  the  push  of  the  gas  is  exactly 
equal  to  the  forward  momentum  of  the  bullet  resulting  from  the 
same  push,  or  MV=smv. 

As  mass  equals  weight  divided  by  gravity,  wc  also  have 
\VV  wv 

= ■,  or  VV\'a=vu.  Stated  another  wav,  that  part  of  the  recoil 

g . S . ’ r- 

velocity  w'hich  Is  caused  only  by  the  acceleration  of  the  bullet  to 

its  muzzle  velocity  varies  directly  with  the  bullet  weight  and  in- 

versely  with  the  weight  of  the  gun. 

The  equation  Fc^MV*-mv%  shows  that  the  same  force,  actii^  for 
the  same  length  of  time  on  two  bodies  which  may  be  of  different 
v^'eights,  will  nevertheless  give  the  same  vMmnxwn  to  each.  This 
does  not,  however,  mean  that  ir  will  give  the  same  kinetic  energy  to 
each. 

To  make  this  dear,  tale  the  following  example;  suppose  a force 
acts  on  an  ohjcci  weighing  100  pounds,  and  gives  it  a vclocirv  of 
(0  feet  per  second;  then  the  same  force  acting  for  the  same  length 
of  time  on  an  object  weighing  10  pounds  will  give  it  a velocity  of 
TOO  feet  per  second. 

The  momentum  mvof  the  first  object  would  he  10 

and  that  of  the  second,— x 100  is  the  sanK. 

^2.16 

The  energy,  /:mv^  is  quite  different  for  the  two  cases.  In  the 

1 100 

first  case  it  is  — x x 10  x 10  2=  15^.472  foot  pounds. 

In  the  second  case  it  is  — x 3*  i;64.72  foot 

2 32.16  ^ ' 

pi>unds,  ten  times  as  great. 

That  is  the  reason  for  the  fortunate  fact  chat  the  recoil  energy  is 
so  much  less  than  the  muzzle  energy  of  the  bullet. 

If  a Springfield  rifle  weighing  8.69  pounds  discharges  a 150  grain 
bullet  at  2700  feet  per  second,  the  recoil  velocity  of  the  gvin  due  co 
the  reaction  of  accelerating  the  bullet  alone  would  be, 
wv  150  X 2700 

V — -TT7-  — - T-T — = 6.612  feet  per  second (a) 

W 7000x8.69  ^ ^ ' 


286 


Hatcher’s  Notebook 


Recoil  Velocity  Due  to  Accelerating  the  Pou'der  Gas 
Now  let  us  look  as  the  second  element  of  the  recoil,  as  mentioned 
above,  which  is  that  part  of  the  recoil  caused  by  the  reaction  of  ac- 
celerating the  powder  gas  to  approximately  half  the  muzzle  velocity 
of  the  bullet,  while  the  bullet  is  still  in  the  bore. 

In  the  example  we  have  taken  the  powder  charge  weighs  approxi- 
mately 50  grains,  or  one  third  as  much  as  the  hiillci.  By  rhe  time  the 
bullet  reaches  the  nnizzle,  the  powder  charge  in  rhe  form  of  gas 
will  fill  the  chamber  and  bore.  As  the  chamber  is  larger  in  diameter 
than  the  bore,  the  center  of  gravity  of  the  powder  charge  will  be 
nearer  the  breech  than  the  muzzle  at  this  time.  It  will  actually  be 
1 2.7  inches  shore  of  reaching  the  muzzle,  and  will  have  moved 
forward  only  10.142  inches  from  its  former  location  in  the  center 
of  the  chamber,  while  the  bullet  was  moving  forward  through  its 
entire  travel  of  21.697  inches.  This  figure  is  arrived  at  as  follows: 
The  barrel  of  the  Springfield  rifle  is  24-rio*'»  inches  long,  und  is  bored 
out  to  a cone  shape  ac  the  rear  end,  giving  a space  for  ihc  from  end  of 
the  bolt  CO  fic  into.  With  normal  tolerances,  the  front  face  of  the 
bolt  extends  into  this  opening  a distance  of  making  the  dis- 
tance from  the  face  of  the  bolt  to  the  muzzle  2^942  inches.  De- 
pending on  tolerances,  the  base  of  the  150  grain  bullet  may  be  from 
2.22"  CO  2,27"  forward  of  the  base  of  the  cartridge,  when  the  bullet 
is  seared  and  crimped  info  place  in  the  cartridge.  The  average  dis- 
tance is  2.245".  Hence,  for  the  usual  siiuation,  the  base  of  the  hnllec 
Is  2.245  inches  for\vard  of  the  face  of  the  bole  when  the  cartridge 
is  in  place  in  the  gun  readv  to  fire.  The  face  of  the  bolt  Is  .064"  for- 
ward of  the  rear  end  of  the  barrel,  so  the  base  of  the  bullet  is  2.309 
inches  forward  of  the  rear  end  of  the  harrei.  The  barrel  is  24.006 
inches  long,  hence  the  travel  of  the  bullet  to  muzzle  is  21.697  inches, 
as  given  on  page  65  of  Ordnance  Pamphlet  1923. 

When  the  loaded  cartridge  lies  in  the  chamber,  the  center  of 
gravity  of  the  powder  charge  lies  approximately  one  inch  in  rear  of 
the  base  of  the  bullet,  or  22.697  inches  from  the  muzzle.  The  cubic 
capacity  of  rhe  powder  space  in  the  cartridge  case  is  .251  cubic 
inches.  The  bore  diameter  is  .300",  and  the  groove  diameter  .308".  The 
grooves  are  three  times  as  wide  as  the  lands.  Therefore,  three-fourths 
of  the  bore  has  a diameter  of  .308",  and  one-fonith  has  a niiameter 
of  .300";  the  average  is  .306". 

The  cross  section  area  of  the  bore  5$  .07354  square  inch.  The 
cubic  contcnc  of  one  inch  length  of  the  bore  is  .07354  cubic  inch. 
The  total  length  ahead  of  the  powder  space  is  21.697"  long  and  has 
a cubic  capacity  of  1.5956  cubic  inches,  which  added  to  the  .251 
cubic  inch  of  pr»wdcr  space  gives  a total  of  1.8466  cubic  inches. 

As  the  bullet  reaches  the  muzzle,  the  powder  gas  will  occupy  all 
this  space  equally,  and  the  center  of  the  mass  ai  gas  will  be  in  the 


The  Thecwy  of  lUroir 


middle  of  ilus  space.  There  will  be  .9233  cubic  inch  of  space  ahead  of 
the  center  of  mass  of  the  gas,  and  the  same  b^ind  it.  .9233  divided 
hy  rhe  cubic  capacity  of  each  inch  of  bore  gives  *2.555  of  bore 

between  the  center  of  the  gas  and  the  muTzle.  Before  rhe  explosion 
it  was  22.697  inches  behind  the  mu/,/.k;  when  the  bullet  reaches  the 
muzzle,  the  center  of  the  gas  is  only  12.555  muzzle,  hence  has 

moved  forward  10.142  inches  while  the  bullet  was  moving  21.697 
inches. 


The  bullet  has  a muzzle  veloci^'  of  2700  feet  per  second  acquired 
while  ir  was  moving  21.697  inches.  During  the  same  time  the  gas 
moved  only  xo.142  inches,  or  46.75  per  cent  as  much.  Hence,  its 
velocity  just  before  bullet  exit  is  46.75  per  cent  of  2700,  or  1262.0 
feet  per  second. 


That  part  of  the  recoil  velocity  given  to  chc  gun  as  a result  of 

accelerating  the  powder  gas  from  zero  to  1262.0  feet  per  second 

, , , c vcT.  of  sas  in  bore  50  x 1262 

would  be  V — X r-f — 7 = 1,03  feet 

weight  of  gun  7000  X 8.60  ^ 


7000 

per  second (b) 


Third  Element  of  Recoil 

This  is  that  part  of  the  recoil  of  the  gun  that  is  caused  by  the 
muzzle  blast  produced  when  the  bullet  leaves  and  the  pent  up  gases 
are  free  to  expand  into  the  atmospheres.  The  gases  then  rush  out  of 
the  muzzle  at  high  velocity,  and  give  the  gun  the  same  kind  of  push 
that  propels  a racket  or  a jet  plane.  In  Springfield  rifle.s,  or  the  Garand 
either  for  rhar  matter,  chc  pressure  of  the  gas  at  the  muzzle  when 
the  bullet  leaves  may  be  anywhere  from  less  than  3000  pounds  per 
square  inch  to  well  over  twelve  thousand,  depending  on  various  fac- 
tors, such,  as  for  example,  the  length  of  barrel;  the  granulation  of 
the  powder  and  its  composition;  whether  it  is  quick  burning  or 
progressive  burning;  etc. 

\Vich  a high  muzzle  pressure,  the  rocket-like  thrust  of  chc  expand- 
ing gas  is  much  greater  than  with  a low  muzzle  pressure,  and  the 
recoil  is  correspond iiigly  intensified.  Shortening  the  barrel  always  re- 
sults in  higher  muzzle  pressure,  other  things  being  equal,  and  there- 
fore increases  recoil,  sometimes  very  noticeably. 

The  physics  of  this  rocket-like  thrust  is  very  w ell  understood  these 
days,  as  a result  of  the  large  amount  of  work  that  has  been  done  on 
both  rockets  and  jet  planes.  The  thrust  on  the  gun  at  any  instant  from 
this  cause  Is  given  by  the  equation: 

Thrust  = Net  Gas  Pressure  at  Exit  x Area  of  the  Exit  x Mass  Race 
of  Discharge. 

The  Net  Gas  Pressure  at  Exit  is  simply  the  average  pressure  of  the 
gas  at  the  muzzle,  less  the  pressure  of  the  atmosphere.  As  this  starts 
at  some  such  figure  as  mentioned  id>ovc  of  3000  to  12000  pounds 
per  square  inch  and  falls  to  zero  in  a fraction  of  a scennd,  its  amount 


288 


Hatch£R*s  Notebook 


for  our  purposes  is  unknown  and  any  figure  we  used  would  be 
merely  guesswork.  The  Area  of  the  Exit»  that  is  the  cross  sectional 
area  of  the  bore  at  the  muzzle  is  easily  calculated  from  the  known 
bore  diameter.  The  Mass  Rare  of  Discharge  is,  like  the  first  term, 
unknown  as  far  as  our  recoil  calculations  arc  concerned. 

About  all  that  this  equation  docs  cell  us  is  chat  higher  the  atmos- 
pheric pressure,  chc  less  the  recoil  due  to  the  muzzle  blast,  for  the 
higher  the  atmospheric  pressure,  the  less  the  Net  Pressure  at  Exit. 
It  is,  of  course,  easily  seen  chat  if  the  air  had  a pressure  equal  to  the 
gas  pressure  itself,  tfie  gas  would  not  come  out  at  ail  and  the  recoil 
from  this  cause  would  be  zero. 

This  has  been  seated  at  some  length  in  chc  hope  of  correcting  a 
common  misapprehension  in  this  regard.  So  often  in  articles  on  re- 
coil we  see  statements  to  the  effect  that  the  recoil  due  to  the  muzzle 
blast  is  caused  by  the  pushing  of  the  powder  gas  against  the  atmos- 
phere. I well  remember  one  article  which,  in  speaking  of  the  M 1903 
Springfield,  stated  chat  “most  of  the  recoil  energy"’  is  due  to  “a 
reaction  between  the  base  of  the  projectik,  chc  circumambient  atmos- 
phere and  the  face  of  the  gun  breech,  with  the  gas  column  as  the 
medium  of  transmission.” 

Both  the  quoted  statements  arc  in  error.  Obviously  “Most”  of  the 
recoil  is  not  due  to  the  ejection  of  die  powder  gas,  but  rather  to 
the  ejection  of  chc  hullcc  insTcad,  in  the  proportion,  for  the  M 1903 
rifle  with  150  grain  service  bullet,  of  64  per  cent  of  the  recoil  velocity 
caused  by  chc  bullet  and  36  per  cent  by  the  gas  ejection. 

The  atmosphere  docs  not  increase  the  recoil;  it  is  well  known  even 
CO  child  science  fans  chat  rockets  work  better  in  a vacuum  chan  in 
chc  air.  Nor  can  chc  thrust  be  transmitted  to  the  face  nf  the  breech 
chrough  the  column  of  gas.  Consider,  for  example,  the  ordinarj'  kwii 
sprinkler,  which  rotates  as  a result  of  the  reaction  of  the  jets.  The 
pressure  of  chc  air  is  not  what  makes  it  go.  It  would  operate  even 
better  in  a vacuum.  Nor,  when  one  of  the  streams  happens  to  pass  a 
tree  or  fence,  will  any  additional  pressure  be  transmitted  back  to 
the  nozzle  through  the  stream  of  water,  any  more  than  one  can  fed 
a reaction  or  increased  pressure  on  a hose  nozzle  from  the  pusli  of  a 
brick  wall  if  the  hose  is  squirted  on  it.  So  let’s  gee  rid  of  this  old 
* resulting  from  the  push  uf  the  powder  uas 

against  rhe  surrounding  atmosphere. 

Practical  Methods  of  Approxhnaimg  Recoil  Due  to  Muzzle  Blast 

In  view  of  the  extreme  difficulty  of  writing  a completely  accurate 
mathematical  formula  that  will  be  ptaccic^  for  use  in  everyday 
calculations  to  obtain  that  part  of  the  n?coil  due  to  muzzle  blast, 
most  authorities  use  some  approximation  that  gives  results  agree- 
ing reasonably  well  with  those  found  by  actual  dynamometer  tests. 


The  T heory  of  RtxoiL 


289 

One  approach  to  the  problem  is  to  consider  chat  the  gas  when 
freed  by  the  exit  of  the  bullet  starts  to  expand  at  a rate  chat  is 
determined  by  chc  pressure  and  dcnsiry  conditions  existing  in  the  bore 
at  chat  time,  and  chat  this  rate  falls  to  zero  as  tlte  gas  roaches  annos> 
phcric  pressure.  It  has  hecn  consideretl  that  ior  modern  rifles 
M ith  pressures  in  the  range  of  the  ordinary  iiiilirary  riHc  of  the  past 
several  decades,  the  gas  starts  to  expand  with  a velocity  of  some  9000 
feet  per  second,  and  that  ihe  rate  falls  to  zero  rapidly,  with  an  average 
value  of  4700  feet  per  second.  Bevis  and  Donovan,  in  The  Modern 
Rifle,  1917,  state  that  experiments  with  a Sicberr  Vdocimeter  lead  to 
the  conclusion  that  a value  of  4700  may  be  used  for  the  exit  velocity 
of  che  gases.  Balleisen,  in  Principles  of  Firearms,  1945,  gives  the 
same  figure. 

For  high  powered  rifles,  this  seen«  to  give  results  char  are  satisfac- 
torily close  to  measured  values.  For  shotguns,  it  is  much  coo  high.  For 
ultra  high  velocity  rifles,  it  is  most  likely  too  low. 

T his  figure  of  4700  feet  per  second  as  rite  average  effeccivc  velocity 
of  the  powder  gases  includes  both  the  motion  of  the  gases  along  the 
bore  before  the  hullec  leaves,  and  the  sudden  expansion  to  atmospheric 
pressure  after  the  bullet  makes  its  exit.  Using  this  figure,  wc  may 
mnv  suite  an  equation  that  will  give  us  a g<wKl  practical  a ppn^xi illa- 
tion to  the  total  recoil  velocity,  including  all  three  of  chc  elements 
iliscnsscd  above.  If  all  weights  are  expressed  in  pounds,  this  formula 

would  he:  V SB ^ (c) 

A Second  Method 

The  British  Text  Book  of  Small  Arnts^  1929,  states  that  “experi- 
ments of  an  extensive  nature  with  ordinary  guns“  indicate  that  the 
average  effective  velocity  of  the  powder  gases  may  be  taken  as  be- 
tween one  and  two  times  the  muzzle  velocity  of  die  bullet,  with  an 
average  value  of  one  and  a half.  The  same  svork,  edition  of  1909, 
gives  a value  of  2 for  the  Short  Lee -Enfield  nsing  cartridges  loaded 
with  cordite. 

la  applying  this  approximation,  a considerable  degree  of  judgment 
will  have  to  be  used,  as  a figure  approaching  the  higher  limit  must  be 
used  for  very  high  pressure  loads  in  short  barrels,  while  low  pressure 
loads,  such  as  are  used  in  sliotguns  and  revolvers,  require  a much 
lower  figure. 

For  rifles  in  the  Krag  class,  a figure  of  1.5  should  he  used,  and 
this  will  work  well  with  re\^oIvers  also,  as  well  as  with  shotguns  hav- 
ing short  barrels  and  usii^  full  loads.  For  shotguns  having  barrels  of 
maximum  length,  a figure  of  1.25  gives  closer  results.  For  guns  such 
as  the  M 1903  Springfield  or  che  Garand,  a value  of  1.75  should  be 
used.  Using  this  latter  figure,  we  can  write  our  formula  as  follows; 


290 


I]aiciilr*s  Notebook 


(w  — j-  c)v 

all  weights  of  course  being  in  pounds;  V = ^ 

(j) 


Lei’s  take  an  example  and  sec  liow  it  works  out  when  compared 
with  actual  measured  results. 

I personally  own  three  service  type  Model  ’03  Springfield  rifles, 
all  purchased  from  Government  Arsenals,  and  all  three  unaltered, 
just  as  they  came.  The  old  original  iVt  1903,  with  straight  stock, 
weighs  8 pounds  6 ounces.  The  1903  Ai,  with  pistol  grip  stock,  as 
issued  weighs  9 pounds  6 ounces.  The  M 1903  A3,  of  war  manu- 
facture, made  by  L.  C.  Smith-Corona,  with  stamped  out  parts,  and 
no  pistol  grip,  weighs  8 pounds  4 ounces. 

Ordnance  Wmphlet  No.  1923  gives  the  wight  of  the  rifle  without 
bayonet  as  8.69  poui^ds  and  the  free  recoil  energy  as  14.98  foot 
pounds.  As  these  rifles  can  vaiy'  so  much  as  to  weight,  principally  on 
account  of  the  differing  densities  of  wood  in  the  stocks  lets  take 
8.69  pounds  as  the  weight  of  the  rifle  in  our  example,  so  as  to  be  more 
nearly  comparable  witn  the  official  pamphlet.  For  the  same  reason  let’s 
consider  muzzle  velocity  of  the  150  grain  flat  base  150  grain  bullet 
to  be  2700  feet  per  second.  That  was  the  figure  to  which  the  old 
M 1906  ammunition  was  loaded;  though  the  present  M:  ball  with 
J50  grain  bullet  is  rated  at  2800  f.s.  muzzle  velocity. 

A Springfield  rifle,  M 1903,  firing  a carti'idge  loaded  with  50 
grains  of  powder  and  a 150  grain  bullet  to  give  2700  f.s.  muzzle 
velocity  would  give  the  following  results  by  the  two  formulae. 

Using  formula  (c),  \vc  would  have  for  the  recoil  velocity: 

,,  150  X 2700  + 4700  X so  , j 

V = T-T or  IO.S2  feet  per  second  recoil 

7000  X 8.69  ^ 

velocity,  and  the  recoil  energy  would  be  54  MV^,  or  !4  x - 

^ 2 • I 

X 10.52  X 10.52,  or  14.95  pounds. 

Using  formula  (d),  we  would  have: 

,,  (150  + *«75  X 50)  2700 

V — T-T or  IO.S4  feet  per  second  recoil 

7000  X 8.69  * 

velocity,  and  the  corresponding  recoil  energy  would  be  1 5.008  foot 
pounds. 

Recoil  Before  the  Bullet  Leaves  the  Gun 


Recently  an  acquaintance  who  is  the  head  of  a large  gun  business, 
and  is  a smart  designer  and  an  inveterate  experimenter,  told  me  that 
the  recoil  takes  place  “When  the  bottle  is  uncorked,”  and  that  the 
gun  does  not  begin  to  move  until  the  bullet  has  left  the  muzzle.  This 
lie  said,  had  been  determined  as  the  result  of  navy  experiments  re- 
port eel  to  him  bv  a Naval  Officer  friend. 

I asked  why,  in  that  case  a revolver  shoots  higher  with  a slow 
heavy  bullet  than  it  does  widi  a fast  light  one.  That  is  a well  known 
fact,  and  he  admitted  that  it  is  so.  After  thinking  it  over,  he  said  that 


Thk  Theory  of  Rk:coiL 


291 

in  revolvers,  no  doubt  some  of  the  recoil  must  cake  place  before  the 
bullet  kaves,  but  chat  it  docs  not  in  large  guns,  as  was  proved  by 
these  navy  experiments. 

Be  that  as  it  jiuy,  every  gun,  large  or  small,  army,  navy  or  civilian, 
starts  Jiioving  backward  at  the  exact  instant  that  the  bullet  starts 
moving  forward. 

Lets  continue  our  experiments  with  that  same  8.69  pound  Spring- 
field  and  its  150  grain  2700  foot  per  second  bullet  and  50  grain 
powder  charge,  and  tind  out  how  far  the  gun  moved  back  before 
rhe  bullet  left. 

In  making  our  calculations,  let  us  use  the  figures  already  developed 
as  to  bullet  travel  and  position  of  the  center  of  gravity  of  the  powder 
cliarge  at  the  instant  of  bullet  exit. 

In  its  travel  to  the  mu//.Ic,  the  bullet  has  ao^uired  a velocity  of 
2700  feet  per  second  and  the  gas  will  have  reached  a velocity  of 
10.142 

2700  ^*21  69"  * second.  When  the  gun  is  fired,  the 

powder  pressure  acts  equally  in  all  directions,  driving  the  bullet 
forward  and  the  gun  back  at  the  same  time  with  the  same  force.  The 
backward  velocity  of  the  gun  times  its  weight  is  at  any  instant  equal 
to  the  forward  velocity  of  the  bullet  limes  its  weight,  plus  the  for- 
ward velocity  of  the  powder  gas  limes  the  weight  of  the  gas. 

Ihc  recoil  velocity  that  the  gun  will  have  when  the  i)ullet  reaches 
the  muzzle  will  be: 

' 7000  X 8.69 = 7 feet  per  second  (e) 

As  the  total  recoil  velocity  is  jo.54  feet  per  .second,  we  see  chat 
the  part  of  the  recoil  velocity  which  occurs  before  the  bullet 
leaves  is  73  per  ceiu  of  the  whole,  and  the  remainder  or  that  part 
due  solely  to  the  muzzle  blast  would  be  27  per  cent,  or  2.805  feet 
per  second. 

It  should  be  noted  chat,  since  the  recoil  energy  is  proportional  to 
the  square  of  the  recoil  velocity^  doubling  the  velocity  will  quadruple 
the  energy.  If  we  had  two  components,  each  of  which  produced  50 
percent  of  the  velocity,  then  what  proportion  of  the  energy  would 
be  produced  by  each?  A little  care  must  be  used  to  avoid  false  and 
jiiislcading  conclusions.  Sup}>ose  the  bullet  reaction  had  produced 
five  feet  per  second  recoil  velocity,  and  the  muzzle  blast  has  pro- 
duced exactly  the  same,  or  five  feet  per  second. 

I'akinc  the  bulkr  effect  first,  we  could  say  that  the  recoil  energy 
was  one^alf  rhe  mass  of  the  gun  multiplied  by  the  velocity  squared,  or 

— and  the  recoil  produced  by  both  rogctlier  would  — 

Thus  we  could  say  the  bullet  produced  25  per  cent,  and  the  muzzle 
blast  75  per  cent,  but  if  we  did,  we  would  be  wrong.  Each  has  pro- 


Thk  Thecwv  oi**  Recoil 


293 

tlucccl  *m  equal  amount  of  the  velocity  \\  hich  is  responsible  for  the 
energy,  and  if  we  had  started  with  the  inu^le  blase  first,  our  results 
would  have  been  reversed,  and  we  would  have  25  per  cent  for  the 
blast,  the  remaining  75  per  cent  for  the  hiillcc.  Obviously,  since  each 
has  produced  an  c<|oal  amount  of  the  velocity,  each  is  responsible 
for  an  e<jnal  amnuiu  of  the  energy  resulting  from  the  combined  ' 
velocities. 

In  the  case  of  the  iVI  1903  rifle,  mentioned  above,  the  recoil  velocity  ' 
of  7.64  feet  per  second  due  to  the  reaction  of  the  bullet  would,  by 
itself,  give  a recoil  energy  of  7.89  foot  pounds  10  die  gun,  and  the 
2.805  feet  per  second  recoil  velocity  due  10  the  muzzle  blase  alone 
would  give  a recoil  energy  of  1.065  pounds  to  the  gun;  but  1 
both  together  would  give  15.008. 

Considering  these  figures,  we  see  that  if  by  the  use  of  a muzzle 
brake  we  could  suppress  all  of  the  2.805  recoil  velocity  resulting 
from  the  blast  effect,  we  would  have  only  8 foot  pounds  or  recoil 
energy  left  out  of  15,  a reduction  of  nearly  half. 

Motion  of  Gun  Prior  to  ttuUe/  Exit 
It  might  in  some  cases  be  of  interest  to  know  how  far  the  gim  has 
moved  back  by  the  time  the  bullet  has  reached  the  mnz/.lc. 

It  follows  from  the  equations  chat  we  have  already  been  using  that 
when  two  objects  of  different  weights  which  are  free  to  move  are 
acted  on  by  the  same  force,  the  product  of  mass  times  distance 
moved  is  the  same  for  each;  or  more  simply,  since  weight  is  pro- 
portional to  mass,  the  weight  rimes  the  distance  moved  in  the  same 
for  each. 


In  the  examples  we  have  been  usii^,  the  weight  of  the  gun  is  8.69 
pounds,  that  of  the  bullet  is  150  grains,  or  150/7000^5  of  a pound, 
and  the  weight  of  the  powder  gas  is  5o/7O0oths  of  a pound.  The 
bullet  moves  21.697  inches  to  reach  the  muzzle,  and  the  powder  gas 
in  the  same  time  interval  moves  10.14:  inches  ahead  of  its  (original 
position  in  the  cartridge  case. 

Therefore,  when  the  bullet  is  ac  the  muzzle,  the  gun  will  have 
moved  back  a distance  D such  that  D times  the  weight  of  the  gun 
equals  bullet  weight  times  21.967  phis  powder  weight  times  10.142,  or 


D X 8.698  = 


i$o 

7000 


X 2 j .697 


10.142 


or 


150  X 21.697  I-  50  X 10.142  .... 

= — 7000x8.69  — = 

The  first  time  I made  this  calculation  was  at  Springfield  Armorv 
in  1920  in  connection  with  the  design  of  an  automatic  weapon.  It 
seemed  desirable  to  check  the  calculations  by  actual  test,  so  my 
brother  Major  James  L.  Hatcher  (now  Colonel)  rigged  up  an 
electrical  circuit  to  measure  if.  He  suspended  the  rifle  on  two  parallel 
wires  12  feet  long,  so  rhat  is  was  free  to  swing  straight  to  the  rear 


294 


Hatcher’s  Notebook 


on  recoil.  A point  connected  to  the  eleccricai  circuit  was  attached 
CO  the  muzzle*  so  arranged  that  when  the  bullet  passed  it  would  make 
contact  and  a spark  would  pass  to  a piece  of  .sensdrized  paper  placed 
nearby.  First  a spark  was  pa.ssed  with  the  gun  nr  rest,  then  the  gun 
was  hrccl.  The  two  marks  on  the  paper  were  slightly  less  than  .07 
inch  apart,  which  was  an  excellent  confirmation  of  the  calculations. 

To  fire  the  gun  without  any  disturbance  from  trigger  pull,  the 
trigger  was  tied  fonvard  with  a string,  and  a rubber  band  was  pLiced 
around  the  trigger  and  trigger  guard.  The  string  was  then  ignited 
with  a match.  When  it  burned  away,  the  gun  was  fired  with  no 
disturbance,  as  the  backward  pull  of  the  rubber  band  on  the  trigger 
was  neutralized  by  its  forward  pull  on  the  trigger  guard. 

'The  calculation  performed  above  will  readily  give  the  distance 
the  gun  moves  before  the  bullet  leaves,  but  it  does  not  tell  us  what 
chc  recoil  velocity  is,  nor  is  there  any  very  ca.sy  way  to  obtain  it 
from  the  distance  moved,  even  though  wc  know  from  the  interior 
ballLsdc  curve  for  this  rifle  and  c-arlridgc,  that  the  motion  is  accom- 
plished  in  .00098  second. 

The  gun  moves  .o6j«3  inch,  which  divided  by  12,  gives  .00515 
foot;  it  moves  this  distance  in  .00098  second,  so  its  average  speed 
over  this  distance  is  5.276  feet  per  second.  Since  the  gun  started  xrom 
a condition  of  rest,  its  velocity  at  the  end  of  this  rime  would  be 
twice  the  average  if  chc  acceleration  had  been  uniform.  However, 
chc  acceleration  was  not  uniform.  It  iitartcd  high,  and  fell  off  rapidly 
as  shown  by  chc  curve  of  velocity  for  the  I mi  Net. 

Moreover,  the  accelerarion  of  the  powder  gas,  which  also  reacts 
on  the  gun,  is  quite  differenc  from  that  of  the  bullet,  and  is  not 
given  on  the  curve.  Hence,  as  stated  above,  the  distance  the  gun 
moves  before  the  bullet  leaves  is  not  of  much  use  to  us  in  getting 
the  recoil  velocity. 

From  the  laws  of  motion  on  which  our  calculations  are  based,  it 
follows  chat  in  the  case  of  a closed  system,  that  is,  up  until  the 
instant  chc  bullet  leaves,  the  center  of  gravity  of  the  system  as  a 
whole  remains  in  the  same  spot,  as  the  different  elements  of  rhe 
system  move  due  to  their  mutual  reactions.  Just  to  check  our  former 
results,  let  us  use  this  statement  as  a basis  for  determination  how 
far  back  the  gun  moves  before  the  bullet  leaves. 

The  bullet  has  a weight  of  i5o/7oooths  of  a pound,  and  its  center 
of  gravity  moves  forward  21.697  inches.  The  powder  gas  has  a w'eight 
of  5o/7oooths  of  a pound,  and  its  center  of  gravity  moves  forward 
10.142  inches.  For  the  forward  movement,  we  therefore  have 
i5o/700oths  X 21.697  ‘i*  jo/Voooths  x 10.142,  or  .5573  pounds-inches. 
The  gun,  weighing  8.69  pounds,  must  have  its  center  of  graviev’ 
move  back  the  same  number  of  pounds-inches  if  the  center  of  gravity 
of  the  system  is  to  remain  in  the  same  spot.  To  fincl  out  how' 
far  the  gun  moves,  divide  this  amount  bv  the  weight  of  the  gun; 


The  Theory  of  Recoil 


295 

•5375  = .06183,  which,  of  course,  is  the  same  figure  that 

was  found  by  the  other  method. 

Effect  of  Recoil  on  the  )uwp  of  Revolvers 

The  handle  nf  a revolver  or  pistol  is  below  the  barrel,  with  the 
result  that  a backward  push  on  the  barrel  of  a handgun  in  the  grasp 
of  a shooter  rends  to  pivot  the  gun  about  the  user's  wrist  and  make 
the  barrel  swing  upward. 

'['he  pressure  in  the  chamber  of  the  .45  caliber  automatic  pistol  is 
from  14000  to  15000  pounds  per  square  inch,  and  as  the  base  of  the 
bullet  has  an  area  of  .159  square  inch,  that  means  that  for  an  instant 
the  pressure  is  driving  the  gun  back  with  a force  of  froni  2226  10 
2385  pounds,  or  well  over  a ton. 

Nothing  that  the  shooter  can  do  towards  holding  the  gun  tighcer 
will  have  much  effect  on  the  motion  caused  by  this  enormous  force, 
which,  fortunately,  lasts  only  a brief  fraction  of  a second. 

The  result  is  chat  at  ordinary  pistol-shooring  ranges  not  greater 
than  50  yards  the  bullet  dischai^d  from  a pistol  or  revolver  will 
inevitably  strike  above  the  point  at  whkh  the  bore  of  the  gun  was 
alined  at  the  instant  of  discharge. 

All  handgun  makers  rake  this  fact  into  account,  whether  con- 
sciously or  not,  in  the  way  they  place  the  sights.  In  order  to  make 
die  bullet  strike  the  spot  aimed  at,  the  barrel  muse  point  below  this 
spot,  so  the  sights  are  always  so  alined  at  the  facn»rv  as  to  make 
the  line  of  sight  rise  above  the  line  of  the  bore  enough  to  correct 
for  the  jump. 

With  the  sights  adjusted  this  way,  the  Inillec  hits  the  spot  at  which 
the  sights  were  pointed  at  discharge,  though  not  the  spot  at  which 
the  l)orc  was  aligned  at  that  instant. 

Users  of  factory  loads  are  not  too  much  bothered  by  this  phe- 
nomenon; in  fact,  they  arc  usually  unaware  of  it,  unless  they  happen, 
for  example  to  use  both  the  regular  .38  Special  cartridge,  with  the 
T58  grain  bullet,  and  the  .38  Special  Soper  Police,  with  its  200  grain 
bullet,  and  to  use  them  in  the  same  gun.  Or,  of  course,  the  .38  S & W 
and  the  corresponding  .38  S & W Super  Police.  Or  something  of 
the  kind. 

The  hand  loader,  however,  who  is  likely  to  use  bullets  of  several 
different  weights  in  the  same  gun,  is  constantly  bothered  by  rather 
large  changes  in  his  point  of  impact.  For  example,  1 have  often  re- 
ceived letters  reading  something  like  this:  “.Mv  .38  Special  Revolver 
is  sighted  for  the  factory  loads,  and  when  I shoot  the  130  grain  wad- 
cuecers  it  groups  low.  Please  give  me  a load  for  this  bullet  that  will 
make  it  group  with  the  factory  load.” 

The  answer  is  rliat  it  can’t  be  done.  The  general  impressions  seem 
to  be  that  if  we  put  in  more  powder,  we  will  make  the  jump  greater 
and  thus  make  the  bullet  hit  higher  on  the  target,  bur  as  a practical 


csmK  Of  GmF  ABOVE  A /mo  pomr 

INCHES 


BULLET  ML/GHT  GRA/f/S. 

/SO  no  170  no  /so  200  z/o 


Rcsulis  of  a series  of  firings  with  a .58  S & W Special  Revolver*  ai  20  >*ar<is,  off  haodt  usiog  loads  with  different  bullet 
weights  froo)  150  co  210  grains,  and  with  powder  charges  of  four,  four  and  a half,  and  five  grains. 

The  heavier  bullets  always  shot  higher  than  the  lighter  ones.  The  heavier  powdei  charges  did  not  seem  to  make  the 
groups  any  higher  than  the  lighter  charges. 


Hatcher’s  NoTEBOoh. 


The  The<»y  of  Recoil 


297 

matter  this  is  noz  so.  If  we  want  to  split  hairs,  w'C  must  admit  that 
the  added  weight  of  the  grain  or  two  of  powder  does  in  theory  cause 
the  gun  CO  jump  slightly  more;  but  this  is  solely  on  account  of  the 
added  mass  to  be  expelled  from  rhe  gun  along  with  the  bullet,  not 
because  of  the  added  velocity.  Tlie  mass  of  the  powder  is  so  in- 
significant compared  with  that  of  die  bullet  as  not  to  be  noticeable. 

To  take  a concrete  example,  it  has  been  found  by  experiment  that 
with  a six  inch  barreled  revolver,  the  200  grain  .38  Special  Super 
Police  bullet  will  strike  4 Vi  inches  higher  on  the  target  at  20  yards 
chan  will  the  158  grain  .38  Special  with  860  feet  per  second  muzzle 
velocity.  While  the  difference  in  impact  at  20  yards  is  4 Vi  inches, 
the  entire  drop  in  crajector)'  for  the  158  grain  standard  velocity  load 
at  that  range  is  only  9/10  of  an  inch.  If  we  could  raise  the  velocity 
of  the  .38  Special  from  860  feet  per  second  to  2000  feet  per  secon<5, 
we  would  raise  its  point  of  impact  only  some  Va  of  an  inch,  and  the 
low  velocity  200  grain  Super  Police  bullet  would  still  strike  nearly 
4 inches  higher. 

Of  course,  raising  the  velocity  of  the  158  grain  bullet  would  greatly 
increase  the  recoil  of  the  gun;  but  at  the  higher  velocity  the  bullet 
wtiuld  gee  away  that  much  sooner,  and  these  two  factors  balance 
each  other,  so  that  for  a bullet  of  any  given  weight  the  amount  the 
gun  moves  before  the  bullet  leaves  is  about  the  same  regardless  of 
velocity. 

For  the  sutulard  .38  Special,  the  velocity  of  recoil  will  be: 

(158  — 1.5  X X.6)  860 

V « - • ■■  = 8.92  feet  per  second,  and  recoil 

cnerg)^  ***  278  fuot  pounds. 

If  the  powder  charge  were  left  out  of  the  calculations,  the  recoil 
velocity  would  come  out  8.63,  and  the  recoil  energy  2.60  foot  pounds, 
which  shows  how  insignificant  the  powder  reaction  and  muzzle 
blase  are  with  smokeless  pistol  and  revolver  lc*ads.  (With  heavy  black 
powder  loads,  such  as  the  40  grain  load  for  the  .45  Colt,  the  result  is 
quite  different,  however.) 

For  the  .38  Special  Super  Police,  with  200  grain  bullet  we  would 
have: 


(200  + i.5  X 4)  710 
7000  X 2.25 


energy  — 3.02  foot  pounds 


9.29  feet  per  second,  and  recoil 


We  have  already  seen  that  the  distance  TT*  that  the  gun  moves 
back  before  the  bullet  leaves,  multiplied  by  the  weiglir  of  the  gun 
i.s  equal  to  the  distance  “I  ” that  the  bullet  moves  while  it  is  in  rhe 


gun,  multiplied  by  the  buUet  weight,  plus  ihc  distance  *‘1”  that  the 
center  of  the  powder  gas  moves,  times  the  weight  of  the  charge, 


29^ 


Hatcher’s  Notebook 


Or  HTitten  in  equation  form: 


DW  = Lw  I I c or  D= 


Lw  + ic 


W 

Taking  a Colt  Officer’s  Model  Revolver  weighing  2.25  pounds, 
let  ixs  see  how  much  it  will  move  back  before  the  bullet  leaves  with 
each  of  the  two  loads  discussed  above;  the  standard  [58  grain  load 
with  3.6  grains  of  powder  at  «6o  feet  per  second,  and  the  200  grain 
Super  Police  with  4 grains  of  powder  at  710  feet  per  second. 

To  figure  how  far  the  gun  moves  back  before  the  bullet  leaves, 
we  muse  know  the  travel  of  the  bullet  to  the  muzzle.  I’ or  the  regular 
J5S  grain  .38  Special  load  in  the  Colt  Officer’s  Model,  this  is  6.75 
inches.  For  the  200  grain  .38  Special  Super  Police,  it  is  slightly  greater, 
as  the  buller  is  set  deeper  in  the  case,  making  the  distance  frotu  bullet 
base  to  muzzle  6.81  inches.  With  the  regular  load  the  center  of  the 
powder  charge  is  3.56  inches  forward  of  its  original  position  when 
the  bullet  leaves.  With  the  200  grain  bullet  this  distance  is  3.62  inches. 

The  distance  the  gun  would  move  back  before  bullet  exit  with 
the  158  grain  load  would  be  in  inches: 

D = 6.75  X 158  + j.5«  X ^.6  _ . , 

.068c  inch. 

7<Mx>  X 2.25 

If  the  powder  were  not  included  in  the  calculation  the  motion 
would  be  reduced  by  .oooK  inch. 

For  the  2<K)  grain  .38  Special  Super  Police,  the  distance  would  he: 

_ 6.8t  X 200  + 3.62  X 4-0  „ ...  , 

» ■"  .0874  and  jf  powder  were  not 

7000  X 2.25  ^ 

considered  this  would  be  reduced  by  .0009. 

If  will  be  observed  that  velocity  docs  not  enter  these  equations, 
so  tliat  raising  the  velocity  would  nor  change  the  result. 


Shot  Gun  Figures 

Ic  is  usually  said  that  ihe  ordinary  shotgun  has  a recoil  of  from 
one  and  a half  to  two  times  that  of  a high  powered  nulitary  rifle. 
A figure  of  from  28  to  30  lbs.  is  often  mentioned.  Lees  see  how  that 
agrees  with  results  calculated  by  the  method  we  have  used  above  for 
rifles. 

My  old  Winchester  .Model  12  weighs  in  at  just  7 lbs  12  oz.,  or 
7%  lbs. 

A duck  load  of  i!4  oz.  of  No.  4 shot  was  found  to  have  549.29 
grains  of  lead,  or  1.23d  oz.,  with  43.04  grains  of  wads,  and  33.39 
grains  of  powder. 

A trap  load  of  oz.  of  7I4  shot  and  3 equivalent  drains  of  powder 
actually  contained  478.33  grains  of  lead,  53.22  grains  of  wads,  and 
24.3  grains  of  powder. 

The  muzzle  velocity  of  neither  of  these  loads  is  known,  so  chat 
a very  important  factor  in  the  recoil  will  have  to  be  estimated.  Let’s 


The  Theory  of  RtcofL 


299 


call  the  muzzle  velocity  of  the  duck  load  1350  f.s,  and  that  of  the 
trap  load  1250. 

The  recoil  velocity  of  the  duck  load  would  then  figure  out: 

V = (549-^9  + 43><H)  »35<>_i_33-39  x 1.5  x 1350 

7000  X 7.75  ” 


7000  X 7.75 


4*74  i-25 


= 15*99  f.s.  and  the  recoil  energy  would  be  30.8  ft.  lbs. 
For  the  trap  load  the  figures  would  be: 
v_  (47^>33  + 53-^0  2+J  x 1.5  x 1250 

7000  X 7.75  7CK10  X 7.75 

J3.09  f.s.  and  the  recoil  energy  would  be  20.645  ft.  tbs. 


84 


XIII 

Notes  on  Gunpowder 

The  name  applied  to  military  propellants  is  an  interesting  example 
of  the  way  in  which  the  uriginat  meaning  of  a word  can  be 
changed.  “Powder”  originally  meant,  and  still  docs  mean,  fine  dust; 
but  at  the  present  time  wc  find  substances  called  powder  which  do 
not  in  any  manner  resemble  dust  and  which  are  not  even  finely 
divided.  For  example,  cannon  powders  are  ordinarily  made  in  big 
grains  several  inches  long  and  perforated  with  longitudinal  holes;  or 
flat  strips  an  inch  wide  and  a foot  or  more  long,  or  even  In  rubes 
4 or  5 feet  in  length. 

The  word  “powder”  was  first  applied  to  propellants  fur  use  in 
H rearms  because  the  fii*st  propellant  was  a black  dust  or  powder  com- 
posed r>f  groiiiui-up  charcoal,  saltpeter  and  sulphur. 

The  reason  this  mixture  explodes  when  ignited  is  because  it  cfimains 
two  fuels,  charcoal  and  sulpfmr,  which  arc  very  inflammable,  and  in 
addition,  another  solid  substance  which  when  heated  gives  off  largo 
ijuantitics  of  oxygen. 

If  you  mix  charcoal  and  sulphur  together  without  the  saltpeter, 
you  \invt  a black  substance  which  looks  in  all  respects  like  the 
primitive  gunpowder  described  above,  and  if  you  light  it,  it  will 
burn,  provided  you  supply  plenty  of  air  to  support  the  comhustioiv 
I'he  oxygen  in  the  air  enters  into  combination  uith  the  charcoal  to 
form  carbon  dioxide  gas,  and  with  the  sulphur  to  form  sulphur 
dioxide  gas.  However,  there  is  no  explosion  because  these  gases  can 
be  formed  only  as  fast  as  air  can  be  brought  into  contact  with  the 
burning  powder  to  supply  the  ncc'cssary  oxygen  for  the  combustion, 
In  other  words,  this  mixture  of  sulphur  and  charcoal  is  a non-explosive 
powder. 

Now,  when  we  mix  powdered  saltpeter  with  it,  we  change  its 
nature  so  that  it  becomes  an  explosive  pow<icr.  The  mi  mice  ic  is 
lighted  it  bums  all  at  once  w*ithour  waiting  for  anv  air  to  come  into 
contact  with  it.  This  is  because  the  saltpeter  is  very  rich  in  oxygen, 
which  ic  gives  up  when  heated.  Thus  the  gunpowder  supplies  its 
own  oxygen  for  combustion  from  within,  and  can  burn  without  any 
outside  air. 

As  nearly  half  the  products  of  combustion  of  gunpowder  arc  gases 
which  occupy  a great  deal  more  space  than  the  solids  from  which 
they  were  evolved,  ic  is  evident  that  the  combustion  of  gunpowder 
results  in  a sudden  expansion  from  the  space  occupied  by  the  original 
powder,  to  the  much  larger  space  occupied  hy  rhe  gases  which  are 


300 


NoTF4  oy  GUNWVDtR 


JOI 

given  off.  Ic  is  this  sudden  expansion  which  causes  the  gunpowder 
ro  exert  force  when  ic  is  ignited.  TIk  heat  of  combustion  adds  to  , 
this  effect  because  hot  gases  occupy  more  space  than  cold  ones. 

Black  powder  relies  for  its  explosive  properties  upon  three  qualities  | 
wliich  are  typical  of  all  explosives.  First,  when  ignited  it  will  hum  ■ 
by  itself  without  aid  from  the  outside  air,  and  this  burning  is  very  \ 
rapid.  Second,  in  burning  it  gives  off  a Urge  amount  of  gas.  Tliird,  j 
a considerable  amount  of  hear  is  evolved. 

lo  he  successful  for  \jsc  as  an  explosive,  a substance  must  possess  , 
all  three  of  these  qualities.  We  have  seen  above  that  there  are  sub-  ! 
stances  which  can  be  burned  and  will  give  off  a large  amount  of  gas  < 
and  heat,  such  as  the  mixture  of  charcoal  and  sulphur,  but  they  do 
not  burn  without  the  aid  of  the  outside  air  and  consequently  they  do 
not  burn  rapidly  enough. 

Wc  do  have  substances  tl»at  will  burn  without  the  a:d  of  outside 
air  and  burn  rather  rapidly,  but  they  must  also  give  off  a la  rage 
amount  of  gas  or  else  there  is  no  explosion.  Thermite,  whicli  is  a 
mixture  of  oxide  of  iron  and  aluminum  powder,  will  bum  rapidly 
without  air  when  ignited,  and  gives  off  greae  heat,  but  it  does  not 
give  off  any  gas,  and  therefore  there  is  no  explosion.  When  this 
powder  is  burned  it  forms  melted  iron  and  slag,  which  latter  is 
alimiimiin  oxide. 

Even  chough  a substance  can  change  from  a .solid  to  a gas  without 
the  addition  of  oxygen  from  the  outside  air,  there  will  be  no  ex- 
plosion unless  the  change  involves  the  liberation  of  hear.  Some  sub- 
stances change  into  gas  railicr  rapidlv,  but  in  doing  so,  instead  of 
giving  off  heat  they  take  up  heat.  Substances  such  as  these  do  not 
Ca^usc  an  explosion  when  they  decomp<^  because  as  soon  as  chev 
have  scarred  to  decompose,  they  chill  the  surrounding  air  so  much 
that  the  action  comes  to  a stop  until  more  hear  cnii  be  supplied. 

A very  familiar  example  is  the  “drv-ice”  in  which  ice  cream  is 
often  packed.  This  is  solid  carbonic  acid  gas,  and  it  can  exist  in  solid 
ftinn  only  at  an  extremely  low  tcni|Krauire.  The  minute  dr\»-ice  is 
exposed  to  air  it  begins  to  give  off  great  quantities  of  gas,  but  in 
giving  off  this  gas  it  absorbs  all  the  heat  around  ic  so  that  the  gas 
can  only  be  evolved  as  fast  as  the  heat  is  supplied.  Thus  you  can  lay 
a big  chunk  of  dry- tee  on  a hot  stove  and  it  will  sizzle,  hiss  and  jump 
around  for  a long  time  but  there  will  be  no  cxplo.sion. 

Thc  backbone  of  gunpowder  is  the  sul>stance  which  gives  off 
oxygen,  and  that  is  the  saltpeter. 

No  doubt  the  original  invention  of  gim|>owdcr  followed  the  dis- 
covery that  when  saltpeter  is  thrown  into  a fire,  it  crackles,  hisses 
and  makes  the  fire  burn  very  much  more  brightly  because  of  the 
oxygen  it  gives  off.  Then  by  mixing  this  saltpeter  with  inflammable 
materials,  ic  was  found  that  exiremclv  hot  fires  could  l>c  made  when 
the  mixture  was  ignited.  Finally,  no  doubt,  the  proper  comhinarion 


302 


Hmchfr's  Norr  book 


OW  Ushi<»ncd  ^{unpowdcr.  Hlack  sp<>rcio|*  powder  vire  FFG-  Tliis  photo- 
^fipb  well  ilJusirates  ib«  tharjcicrisik  grain  ^hape  of  Mack  powder.  Ibe 
ii)£^reJiems  are  lirsi  made  inii>  large  sized  grains  sshicli  are  {>olidied.  ibcn  broken 
il  too  large  in  size.  The  rounded  and  polished  sarf.ues  ol  the  original  grains 
as  wcU  as  the  fractured  siirfacej  can  be  plainly  seen.  Macnibed  20  times. 


Notes  on  Gunpowder 


30J 

was  obtained  so  chat  when  one  of  these  mixtures  was  ignited  it  went 
off  with  a real  explosion. 

The  actual  discovery  of  gunpowder  is  variously  ascribed  to  the 
Hindoos,  Co  the  Chinese^  and  to  Roger  Bacon,  an  ^Jiglish  philosopher 
who  seems  to  have  described  its  composition  in  a manuscript  written 
ill  1 249. 

Whoever  may  be  the  true  inventor  of  gunpowder,  guns  and  cannon 
were  known  before  1350  A.  D.  From  this  time  imtil  the  discovery  of 
giiiicorton  in  1846,  black  powder  was  the  only  explosive  commonly 
known  and  used. 

The  average  composition  of  black  powder  is,  saltpeter  75  parrs 
by  weight,  sulphur  lo  parts,  and  charcoal  15  parts.  'Hiere  is,  however, 
quite  a wide  variation  in  compositions  that  have  been  used  in  different 
years.  Powders  used  for  blasting,  for  example,  are  more  effective  if 
they  do  not  operate  quite  as  quickly*  as  the  ordinary  gunpowder 
This  is  for  rhe  reason  chat  in  blasting  it  is  desired  to  rend  the  rocks 
and  tear  them  out  in  chunks  rather  than  to  break  them  up  in  fine 
pieces,  which  a stronger  powder  would  do.  I'hc  average  blasting 
powder  would  have  about  70  parts  saltpeter,  14  parts  sulphur  and 
16  parts  charcoal,  but  some  powders  of  this  kind  have  been  made 
with  compositions  as  low  in  saltpeter  as  40  parts,  with  30  part.s  of 
sulphur  and  30  of  charcoal. 

In  the  manufacture  of  gunpowder  the  three  ingredients  are  ground 
up  very  fine  and  then  mixed  together  in  a machine,  after  which  the 
mixed  material  is  given  2 or  3 per  cent  of  moisture  and  put  through 
a process  known  as  incorporation.  This  is  the  most  important  process 
in  the  manufacture  of  black  powder,  its  object  being  to  bring  rhe 
ingrcilteiirs  into  the  closest  possible  contact  so  that  each  parciac  of 
rhe  resultant  ‘‘cake’’  shall  be  composed  of  the  three  ingredients  in 
the  proper  proportion.  This  incorporation  is  done  in  a mill  of  the 
edge-roller  type,  which  is  a big  circular  plate  on  which  two  massive 
rollers  move  round  and  round  in  circular  paths. 

After  the  incorporation,  the  “cake**  is  broken  into  lumps  of  uniform 
size  in  a machine  with  two  pairs  of  grooved  cylinders,  arranged  one 
pair  above  the  other.  The  product  of  this  breaking-down  machine  is 
called  ‘‘powder  meal.” 

In  order  dm  the  powder  may  be  granulated,  the  powder  meal  is 
first  pressed  into  solid  compact  cakes,  called  prcss-cakes,  which  is 
done  in  a hydraulic  press.  The  press-cakc  is  broken  up  into  grains 
by  passing  it  through  a granulating  machine  c<msiscing  of  a series  of 
pairs  of  metal  cylinders  with  teeth  of  suitable  size  and  suitably  placed 
on  the  surfaces  of  the  cylinders.  There  is  a screen  under  each  pair 
of  rollers  to  catch  die  broken  press-cake  and  conduct  the  large  pieces 
CO  the  next  set  of  rollers. 

After  this  granulating  process,  the  powder  is  separated  hy  a series 
of  screens  into  grains  of  different  sizes.  The  last  process  is  polishing, 


Notes  on  Gunpowokk 


305 

which  consists  in  placing  the  powder  in  a wooden  barrel,  and  revolv- 
ing the  barrel  for  5 or  6 hours.  This  removes  all  the  sharp  corners 
and  produces  a hard,  glazed  surface.  Usually  a lircle  bit  of  graphite 
is  included  to  give  additional  polish. 

Tl^e  speed  of  burning  of  black  powder,  and  tlicrcfore  ro  a certain 
degree  its  blrength,  is  com* rolled  by  the  size  of  granulation.  Pow'dcr 
with  extremely  larec  grains  bums  more  slowly  than  a Hnc -grain 
powder,  and  therefore  is  less  sudden  in  its  action.  Also  large -grain 
powder  i.s  much  harder  to  ignite. 

As  the  size  of  the  gi'anularion  decreases  the  strength  of  the  powder 
increases  up  to  a certain  point.  However,  when  a powder  is  made 
very  fine,  lilcc  dust,  the  S|Ked  of  burning  is  again  reduced  because 
all  the  spaces  between  the  grains  arc  filled  up  and  hence  there  is  no 
way  for  flame  to  communicate  itself  rapidly  and  ignite  the  whole 
charge  at  one  time,  as  would  occur  with  powder  of  larger  granulation. 
Powder  with  ver\*  small  grains  is  the  easiest  to  ignite,  however, 
hence  this  kind  of  powder  was  used  for  priming  charges  in  the  old 
muzzle  loaders. 

Black  powder  ns  at  present  made  and  sold  to  the  trade  comes  in 
irregular,  shiny,  metallic  looking  black  grains  designated  as  ro  size 
hy  the  Icrrcrs  Fg,  FFg,  FFFg,  etc.;  the  more  F’s,  rhe  finer  rhe  grain. 
There  is  also  a special  granulation  used  in  the  Army  for  saluting  pur 
poses  called  Grade  A-i.  If  has  often  been  asked  just  whar  these 
di/Tcrene  designations  mean  as  to  size.  This  is  a rather  difficult  ques* 
tion  because  the  designations  vary  with  the  different  manufacturers; 
hue  taking  the  du  Pont  Company’s  system,  the  values  would  he  as 
given  in  rhe  table  below. 

The  powders  arc  measured  by  screening  them  through  a coaiNt 
screen  which  catches  all  the  very  large  lumps,  letting  the  rest  fall 
onto  a very  line  screen  which  allows  all  tlic  very  fine  powder  to  pass 
through.  The  screens  through  which  the  different  grades  of  powder 
must  pass,  and  those  on  which  they  must  be  retained,  are  given  in 
the  cable,  tlie  figures  representing  the  number  of  meshes  per  inch 
in  the  screen. 

Mwt  He 

Size  Must  Pm  Retained  Ov 


Grade  A-i  

6 

10 

•'■g 

14 

16 

FFg  

16 

24 

FFFg  

24 

46 

FFFFg  

4^ 

60 

S7ftokeies5  Po\i\ie 


The  discovery  of  nitroglycerin  in  1^46  opened  a new  field  of  ex- 
plosives. Nitroglycerin  is  one  of  the  strongest  explosives  known,  and 
is  the  basis  of  many  modern  explosive  compounds.  It  is  a colorless, 


HAiclirR’s  N(m:B(K>K 


N0TI*:s  on  GuNiKiu’or.R 


307 

oily  liquid  formed  by  the  action  of  nicric  and  sulphuric  acids  on 
glycerin. 

Nitroglycerin  differs  frou)  gunpowder  in  that  it  is  not  a mixture 
of  fuels  and  oxidizing  agents;  instead,  it  is  a chemical  compound 
containing  a large  amount  of  oxygen,  and  this  chemical  compound 
is  capable  of  rearranging  itself  into  more  stable  compounds  which 
arc  gases.  A sharp  shock  will  cause  this  rearranging  process  to  start, 
and  when  once  started  it  spreads  almost  instantly  throughout  the 
entire  mass,  thus  resulting  io  a violent  explosion. 

Years  ago  when  nitroglycerin  was  first  invented,  it  is  said  that 
a promoter  tried  to  get  miners  interested  in  its  use,  hut  they  looked 
with  suspicion  upon  this  soupy  substance  as  an  exphxsivc  instead  of 
ihc  commonly  used  black  powder  with  which  everyone  was  thor- 
oughly familiar.  Finally  in  one  little  frontier  mining  town  the  agent 
ran  out  of  money  entirely  and  could  not  pay  his  hotel  bill,  so  the 
proprietor  of  the  hotel  rook  his  suitcase  containing  several  quarts 
of  nitroglycerin  as  security.  Apparently  tltc  salesman's  claims  for 
the  explosive  properties  of  his  stock  in  trade  had  not  made  a very 
great  impression,  for  the  suitcase  was  allowed  to  stand  for  some 
months  in  the  upstairs  hall,  where  the  V»ootblack  used  it  for  his 
ms  comers  to  rest  their  shoes  on  while  they  were  being  polished. 
Finally  this  gentleman  noticed  that  sonic  red  smoke  w'as  coming  out 
of  the  suitcase,  and  reported  this  to  the  proprietor,  who  then  re- 
membered that  the  man  who  left  the  suitcase  had  spoken  about  an 
explosive.  It  suddenly  occurred  to  the  proprietor  rnar  it  might  be 
dangerous  to  keep  a suitcase  of  explosives  in  the  house,  so  he  promptly 
carried  it  to  the  back  window  of  the  hall  and  threw'  ic  out  into  a 
vacant  lot.  A two-story  fall  is  not  good  for  any  nitroglycerin  but  is 
especially  bad  for  nitroglycerin  which  has  had  its  temper  consider- 
ably sensitized  by  partial  decomposition,  and  the  result  was  that  the 
suitcase  exploded  with  a detonation  which  shook  the  entire  neighbor- 
hood, and  blew  the  back  out  of  the  hotel.  But  at  least  the  incident 
gave  w'idc  publicity  to  the  fact  that  the  salesman  was  right  when  he 
claimed  to  have  a powerful  explosive. 

Nitroglycerin  is  inconvenient  to  use  by  itself  as  it  is  subject  to 
leakage,  and  thin  films  of  niuoglycerin  leaking  out  on  the  outside 
of  containers  are  subject  to  friction  which  might  easily  cause  dis- 
astrous explosions.  Moreover,  pure  nitroglycerin  is  inconveniently 
sensitive.  It  was  soon  found  that  unless  something  could  be  done  to 
overcome  these  disadvantages,  nitroglycerin  would  never  attain  great 
popularity  as  an  explosive. 

The  difficulty  was  finally  overcome  by  the  discovery  that  nitro- 
glycerin absorbed  into  a porous  substance  made  a much  safer  and 
more  convenient  explosive  than  the  pure  nitroglycerin.  One  of  the 
most  successful  methods  of  using  it  was  to  allow  the  nitroglycerin 


HaTCIIIlR8  Notkhwk 


308 

to  be  absorbed  in  a porous  earth  called  Kieselguhr.  Nitroglycerin 
absorbed  in  a porous  substance  of  this  kind  is  called  Oynamite, 

Another  very  powerful  explosive  which,  like  nitroglycerin,  is  a 
chemical  compound  and  not  a mixture,  is  guncotton.  This  is  formed 
by  the  action  of  nitric  and  sulphuric  acids  on  cotton  or  any  other 
kind  of  cellulose.  Hence  wc  often  hear  the  term  ‘‘nitrocellulose” 
used  instead  of  “guncotton.”  Guncotton  has  the  quality  of  being  a 
substance  which  boras  with  extreme  rapidity.  It  is  said  chat  ic  burns 
so  fast  that  if  some  black  powder  grains  arc  laid  on  guncotton  and 
the  guncotton  is  ignited,  it  may  bum  out  from  under  the  black 
powder  grains  without  setting  them  on  fire. 

Some  chemical  students  are  said  to  have  played  a joke  on  their 
laundress  by  nitrating  a handkerchief  by  soaking  it  in  nitric  and 
sulphuric  acids.  After  the  process  the  handkerchief  looked  just  the 
same  as  it  did  before,  the  only  difference  being  that  it  was  then  if 
guncocten  handkerchief.  They  then  sene  it  to  the  laundress,  and  when 
she  touched  it  with  a hot  iron  it  simply  disappeared  so  quickly  that 
she  did  not  know  what  had  happened,  and  the  students  were  much 
amused  at  her  agitation  when  trying  to  explain  where  the  handker 
chief  went  to. 

Guncotton  is  much  too  quick  in  exploding  for  use  in  guns.  At  first, 
attempts  were  made  to  use  ic  in  this  way  but  they  always  resulted 
in  bursting  or  damaging  the  firearm.  It  was  finally  found  that  bv 
mixing  nitroglycerin  with  guncotton  a double  purpose  was  scr\’c^. 
First  there  was  a substance  to  absorb  the  nitroglycerin  and  decrease 
its  sensitivity  the  same  as  the  Kieselguhr  does  in  tiynaniire.  Second, 
this  same  absorbing  substance  was  itself  a powerful*  explosive. 

Various  explosives  arc  formed  in  this  way.  One  sucli  explosive  is 
the  English  smokeless  powder.  Cordite,  which  is  extensively  used  in 
Great  Britain.  Cordite  Mark  I is  composed  of  37  parts  of  guncotton, 
58  parts  of  nitroglycerin  and  5 parr^  of  vaseline. 

Another  explosive  formed  by  mixing  guncotton  and  nitroglycerin 
is  blasting  gelatin.  This  mixture  is  a very  fortunate  one  chcmicallv, 
because  guncotton  contains  insufficient  oxygen  to  turn  all  of  its 
cait>on  completely  into  carbon  dioxide,  while  nitroglycerin  has  too 
much  oxygen.  By  mixing  the  nvo  substances  in  proper  proportions 
the  excess  of  oxygen  in  one  explosive  supplies  the  deficiency  in  the 
other,  and  the  products  of  the  explosion  olf  such  a inixrnre  arc  nitro- 
gen gas,  carbon  dioxide  gas,  and  water  (in  the  form  of  steam). 

Ic  will  be  remembered  chat  gunpowder  is  merely  a mixture  of  two 
fuels  and  one  oxidizing  agent,  whereas  guncotton  and  nitroglycerin 
are  definite  chemical  compounds.  Such  compounds  in  general  explode 
more  violently  chan  simple  black  powder,  and  arc  known  as  high 
explosives.  Moreover,  there  is  a big  difference  in  the  manner  of 
explosion  of  a high  explosive  as  compared  with  that  of  black  powder. 
When  black  powder  is  ignited  it  burns  with  very  great  rapidity, 


Notes  on  GL-Niwvniot 


309 

giving  off  a large  volume  of  gas,  and  chis  burning  is  the  only  ex- 
plosion that  occurs.  On  the  other  hand,  many  high  explosives  such 
as  guncotton,  nitroglycerin  and  T.  N.  T.  can  be  burned  without 
causing  any  explosion  at  all.  A stick  of  dynamite,  for  example,  can 
be  cue  up  and  tlirown  into  a fire  hie  by  bit  with  very  little  danger  of 
exploding,  though  each  piece  will  burn  rather  intensively,  in  the 
same  way  T.  N.  T.  can  somctiines  l>c  burned  in  large  quantities 
without  any  explosion  occurring. 

What  these  explosives  need  to  cause  them  to  exert  their  full  power 
is  a shock  which  starts  a chemical  rearrangement  of  rhe  jiiolecules 
into  gas  instead  of  solids.  This  chemical  rcarranccnienc  is  called  a 
'detonation.*’  Once  a detonation  is  started  in  a high  explosive,  it 
spreads  through  the  entire  mass  with  a sore  of  wave  action  with 
great  rapidity.  The  speed  of  detonations  varies  in  dilTerenr  explosives, 
hut  in  some  it  is  as  high  as  7000  yards  in  a second.  A detonating  fuse 
consisting  of  a long  thread  of  T.  N.  T.  encased  in  a lead  covering  will 
thus  set  off  almost  instantly  a number  of  different  charges  of  explosive, 
'separated  by  considerable  distances,  if  a deronaring  cap  is  exploded 
at  one  part  of  the  fuze.  Ordinarily  the  detonarum  of  high  explosives 
is  started  by  exploding  a blasting  cap  in  contact  with  them.  I'hesc 
blasting  caps  contain  fulminate  of  mercury,  a substance  tlim  explodes 
with  great  suddenness  and  which  seems  particularly  well  adapted  m 
producing  detonations. 

Another  method  of  using  guncotton  to  make  explosives  besides 
mixing  it  with  nitroglycerin  wa.s  tinally  evolved,  and  this  consists  in 
dissolving  the  guncotton  in  a mixture  tff  ether  and  alcohol,  thus 
forming  a ma$.s  called  a colloid,  having  very  much  the  .same  consist 
ency  as  melted  glue.  T'his  colloid  is  H|nee/.cd  out  into  tubes  like 
macaroni,  and  these  tubes  arc  cue  into  sliorr  lengths,  after  which 
rhe  ether  and  alcohol  used  to  dissolve  the  gunc<it(ou  :u*e  evaporated 
off.  leaving  a hard  substance  something  like  dried  glue.  This  dried 
out  colloid  of  guncotton  is  what  most  modern  smokeless  powders  arc 
made  of.  Such  powders  are  the  old  Government  Pvro  used  in  190^ 
for  Springfield  cartridges;  the  du  Pont  No.  1147  and  No.  1185 
powders  used  in  the  old  .Mi  cartridges  with  its  172  grain  l>oatrail 
bullet;  and  the  iiew^cr  IMR  4895  used  in  World  \Var  H in  the  .^o 
Cal.  M2  cartridge.  Powders  like  these  containing  nitrocellulose  onlv 
and  no  nitroglycerin  arc  called  single  base  powders. 

Such  smokeless  powders  arc  made  in  the  form  of  small  cylindrical 
grains  with  a hole  running  through  the  center.  In  other  words,  they 
.ire  like  little  sections  cut  from  a fine  rube  of  macaroni.  The  object 
of  having  the  hole  through  the  center  of  the  powder  grain  is  to 
control  the  rate  of  burning  so  as  to  hold  up  the  pressure  of  the 
powder  as  long  as  possible. 

The  great  trouble  with  getting  high  velocity  in  a gun  is  the  fact 
that  when  the  powder  in  the  canridge  is  ignited  it  turns  into  gas, 


^(O 


IfviaiKKb  Noiki»k)k 


r ^ 

A nuKivrn  ^mok«lev«  riHc*  jvm'Jcr.  DuPontS  improved  miliiarv  riHc  ]H>wdcr 
No.  Thi$  powder  is  nude  in  the  form  of  liulr  t>linders  nearly  a K*ncl» 

of  an  inch  lon^  svith  a hole  through  ihe  cemer  of  each.  Actual  leogdi  of  the 
grain:  xcven  and  a half  hundredths  of  aa  inch.  Diameter:  two  and  a half 
hundredths.  This  powder  is  used  in  loading  >ervKc  cariridgev  for  the  Spring' 
field  ride. 


Nnits  <IN  Gl*NPO\VnFR 


OuPonc  improved  miliury  rifle  powder  No.  illO.  Magnified  20  times 


Haichkrs  N<rl>.HOOK 


312 

aiul  this  gas,  confined  in  the  small  space  of  the  cartridge  case,  creates 
a very  high  pressure  ^diich  pushes  the  bullet  along  the  bore  of  the 
gun.  But  as  soon  as  rlie  ballet  starts  to  move  along  the  bore,  that 
leaves  more  space  for  the  gas  to  occupy,  hence  there  is  less  pressure, 
and  the  effect  of  the  powder  will  rapidly  fall  off  ro  nothing  unless 
special  means  arc  taken  to  keep  the  pressure  up. 

One  of  these  special  means  is  the  perforation  of  the  powder  grain, 
which  causes  it  to  have  a larger  burning  surface  as  the  combustion 
proceeds.  This  is  because  the  primer  flash  ignites  the  inside  of  the 
tube  as  well  as  the  outside  of  the  grain.  As  the  grain  burns,  the  out 
side  surface  gets  smaller,  hence  the  rate  of  evolution  of  gas  would 
tend  to  decrease;  hut  at  the  .same  time  the  inside  of  the  perforations 
burn  away,  and  the  diameter  of  the  hole  becomes  larger,  with  a 
corresponding  increase  in  the  inrerior  burning  surface. 

The  balance  between  these  two  surfaces  can  be  controlled  by  the 
ratio  of  the  inside  diameter  to  the  outside  diameter  in  the  Hnishccl 
grain  of  powder.  In  cannon  powders  with  their  larger  grains,  there 
arc  usually  seven  perforations  instead  of  one. 

Another  method  of  controlling  the  burning  of  the  powder  and 
making  it  more  progressive,  that  is,  making  it  hold  up  its  pressure 
longer  during  the  travel  of  the  bullet,  is  by  coating  the  powder  with 
.1  substance  which  makes  it  burn  slowly  at  first.  As  this  coating  burns 
<jff  the  outside  of  the  powder,  the  speed  of  combustion  increases. 
These  progressive-burning  powders  tend  to  give  a more  uniformly 
distributed  pressure,  sustained  longer  during  the  travel  of  the  bullet. 
Moreover,  the  maximum  pressure  is  not  so  high  because  instead  of 
being  exerted  all  at  once,  the  pressure  is  spread  onr  more  evcniv 
during  the  entire  travel  of  the  bullcr.  The  du  Pont  ‘‘Improved  Mill 
cary  Rifle’  powders  such  as  1.  M.  R.  No.  3031,  I.  M.  R.  No.  43u» 
and  I.  M.  R.  No.  4064  arc  progressive  powders. 

Like  black  powder,  smokcles.s  powders  arc  also  controlled  as  to 
their  speed  <^f  burning  by  the  grain  si/a:.  Powders  witli  vcr\'  Hiu* 
grains  burn  up  in  a hurry  and  therefore  are  particularly  suited  for 
short-barrel  weapons.  Powders  with  very  large  grains  take  longer 
to  burn  up,  and  are  adapted  to  long-barrel  weapon.s  such  as  cannon. 

Lor  any  given  size  of  gun,  such  as  the  caliber  .30  rifle,  there  is  a 
granulation  of  powder  that  is  suitable,  and  a larger  or  smaller  size 
will  either  give  too  high  pressures  or  wdll  not  burn  up  completely 
before  leaving  the  barrel, 

However,  in  the  Springfield  rifle  the  grains  mav  be  either  long 
and  slender  or  short  and  fat.  In  general,  better  results  are  obtained 
if  the  grains  are  long  and  slender,  because  this  leaves  larger  air 
spaces  between  them  for  the  priming  flame  to  penetrate,  and  thus 
better  ignition  is  obtained. 

For  example,  when  1 was  at  Frankford  Arsenal  some  ycai*s  ago, 
we  were  loading  the  National  Match  ammunition  with  du  Pont 


Notes  on  Gukpo\m)er 


No.  I.  i\1.  R.  No,  1 147,  whicli  was  similar  to  the  modem  L M.  R.  No. 
4320.  This  powder  was  cut  into  very  shore  grains  only  a twenty- 
second  of  an  incli  long,  and  they  would  pack  verj’  uniformly  in  the 
loading  machine  powder  measure,  and  the  variation  between  the 
highc.se  and  the  lowest  charge  in  a test  sample  of  cartridges  would 
be  no  more  than  six  tenths  of  a grain. 

We  then  tried  a very  similar  powder  W'ith  the  grains  cut  twice  as 
long,  that  is,  eleven  to  the  inch.  Tlie  charges  thrown  by  the  loading 
machines  were  not  as  uniform,  having  a maximum  variation  of  about 
' a grain  and  seven  tenths  from  one  cartridge  to  another  from  the 
same  machine.  But  on  machine  rest  tests  the  coarser  powder  made 
smaller  groups  every  time.  Naturally  wc  loaded  the  ammunition  with 
I this  more  accurate  powder,  and  tfie  scores  at  Camp  Perry  ran  ex- 
ceptionally high  that  year.  But  the  Ordnance  Department  came  in 
I for  some  very  sarcastic  and  bitter  criticism  from  a self  appointed 
local  dispenser  of  wisdom  at  the  matches  who  carefully  pulled  the 
bullets  from  a number  of  cartridges  and  weighed  the  charges,  then 
spread  the  word  that  the  extreme  variation  between  charges  was 
twice  as  great  as  it  had  been  the  year  before. 

The  critic  was  accusing  the  Deparcinein  of  very  great  stupidity, 
and  could  not  understand  why  in  the  world  they  used  a powder 
that  did  not  load  quite  as  closely  as  to  weight  variations  as  the  finer 
powder.  lie  talked  loud  and  long  and  no  doubt  there  are  matw  who 
gained  the  iniprcs.'iion  from  him  that  it  was  a matter  of  indifference 
to  the  makers  of  the  ammunition  whether  the  accuracy  \vas  good 
or  had. 

Acrvially,  this  critic  knew  nothing  whatever  about  powder  or  the 
probiems  of  loading  small-arnis  ammunition.  He  just  weighed  the 
charges  in  some  carrridges,  and  found  that  the  variation  was  about 
.1  grain  and  a half;  and  he  hciird  that  the  variation  was  less  with 
the  finer  powder,  so  he  at  once  began  to  shout  his  discovery,  I 
suppose  it  never  occurred  to  him  that  the  Ordnance  engineers, 
with  all  their  vast  testing  resources  and  their  viral  interest  in  pro- 
ducing the  best  possible  ammunition,  had  made  hundreds  of  tests 
much  more  elaborate  than  any  shooter  could  ever  afford  before  they 
finally  decided  to  use  the  large-grain  powder  instead  of  the  other. 
Truly,  a little  knowledge  is  a dangerous  thing. 

Besides  the  nitrocellulose  powders  described  above,  there  are  some 
military  rifle  powders  containing  a certain  proportion  of  nitro- 
glycerin as  well  as  nitrocellulose.  The  old  W-A  (Whistler  Aspinwall) 
powder  used  in  the  early  Krag  cartridges  was  an  example.  It  con- 
tained about  30  per  cent  or  more  of  nicrogiyecrin  and  was  a good 
powder  except  tnat  It  was  erosive  on  the  barrels,  as  nitroglycerin 
powder  bums  at  a higher  temperature  than  nitrocellulose  powder. 

HiVel  No.  3 is  a modem  nitroglycerin  powder  which  lias  gained 
a great  reputation  for  extreme  accuracy  in  march  loads.  BuUseye  is 


3H 


Haix-hrr’s  NaiujooK 


a nitroglycerin  pistol  powder  which  is  still  iLsed  by  the  Government 
in  loading  pistol  cartridges.  Three  types  of  pistol  powder  are 
standard  with  che  Goveriiiiient,  one  a nliroglvcerin  powder,  the  other 
a nitrocellulose  powder  and  the  third  the  so-called  Ball  Powder. 
Tlie  iiicrocellalo.se  powder  that  che  Govcrniiienc  was  using  in  pisto! 
cartridges  during  che  latter  part  of  World  War  II  was  dii  Pont  476^. 

These  pistol  powders,  unlike  the  rifle  powder  above  mentioned* 
do  not  have  tubular  grains.  Instead  they  arc  in  the  form  of  very 
fine,  thin  wafers,  flakes,  or  spheres,  shapes  which  makes  them  burn 
with  the  greater  rapidity  that  is  ncccssar>'  to  cause  rheiri  to  be  con- 
sumed in  the  short-l)arrcl  weapons  in  which  they  arc  used. 

The  rate  of  burning  of  the  powders,  above  described,  such  as 
the  du  Pont  I.  M.  R.  powders  and  the  Hercules  HiVel,  depends  not 
only  upon  the  grain  size  but  also  upon  che  resistance  that  the  bullet 
offers  to  being  moved.  If  any  of  these  powders  are  ignited  in  che 
open  air  they  will  burn  slowly,  the  same  as  a pile  of  grains  of  celluloid, 
and  there  will  be  no  explosion.  On  the  other  hand,  when  they  arc 
iwiced  in  a gun  the  first  grains  burn  and  give  off  hot  gases,  and 
these  hot  gases  in  turn  accelerate  the  burning  of  the  ocher  grains. 
The  more  the  gases  are  confined,  the  hotter  they  arc  and  the  faster 
the  combustion  of  the  remaining  powder  will  be.  Tims  with  a heavy 
hullet  or  with  che  cartridge  case  full  of  powder,  che  combustion  is 
more  rapid  than  it  is  with  a light  bullet  or  with  the  cartridge  case 
(jnly  partly  filled  with  powder. 

There  are  some  powders  which  arc  required  to  burn  with  a large 
air  space  in  the  ca.se,  and  a light  bullet.  Tliesc  arc  powders  used  for 
reduced  loads.  There  arc  also  powders  which  arc  required  to  burn 
with  no  resistance  at  all  in  the  form  of  a bullet  to  hold  back  the 
gases.  This  is  the  case  with  powder  used  in  l>bnk  cartridges,  where 
there  is  no  bullet  but  only  a paper  wad.  This  powder  muse  burn  with 
extreme  rapidity  under  low  pressure.  Tlie  powder  most  used  for  this 
purpose  is  call^  “E.  C.  Blank  Fire  Powder"  (Frcmi  the  originators 
the  Explosives  Company). 

We  have  seen  chat  guncotton  burns  with  extreme  rapidity.  If  wc 
mix  it  with  nitroglycerin  it  burns  more  slowly.  If  we  should  com- 
press it,  or  mix  it  up  with  glue,  or  do  anything  to  take  away  its 
fluffy  consistency,  this  would  tend  to  make  it  burn  more  slowly" 

Following  these  principles,  blank  powder  can  be  made  by  taking 
nitrocellulose  or  some  other  nitro  compound  such  as  nitru-lignln 
(nitrated  wood)  in  coinbinatioD  with  other  suitable  substances,  and 
dampening  the  fluffy  material  with  gum  water,  then  rolling  it  into 
little  balls  or  grains.  Thus  it  is  almost  guncotton,  but  the  violence 
of  its  burning  is  reduced  by  the  fact  that  its  particles  are  glued  to- 
gether by  the  gum  water  solution.  Blank-cartridge  powder  must  not 
be  used  with  a bullet  or  charge  of  shot  in  the  cartridge.  The  added 
resistance  is  liable  to  cause  it  to  detonate  and  blow*  rhe  gun  to  pieces. 


Norrs  on  (junpowdfr 


3*5 


A popular  dense  piscol  pvwelef,  DuPont's  Pisiol  Powder  No.  5.  It  consists 
ui  fine  flakes  of  oicroceHtilose.  Magnified  20  timcv 


f^AICWR^S  NotFBOOK 


DuPont  OvaJ.  A pro|;fe5sivc  shutgiio  powder  designed  to  give  maximum  re- 
sults in  long  fringe  loadk 


NVj^s  on  Gumpowukk 


317 

Powder  for  reduced  loads  is  midway  between  blank-iire  powder 
and  the  regular  rifle  powder.  It  has  to  be  fast  burning  because  it 
cannot  depend  much  upon  the  resistance  of  the  bailee.  It  is  used 
in  small  charges  in  big  cartridge  cases  with  lots  of  air  space,  and  it  is 
also  used  with  very  light  bullets.  It  is  difficult  to  make  a powder  chat 
will  perform  well  under  these  circumstances,  but  this  was  finally 
accomplished  and  an  extremely  satisfactory  powder  of  this  kind  in  its 
day  was  the  old  Sporting  Rifle  Powder  No.  80,  which  wa.s  used  with 
the  gallery-practice  outfits  issued  to  the  Army  .some  years  ago.  This 
powder  is  no  longer  made,  having  been  superseded  by  the  riibiilar 
grain  du  Pont  No.  4759. 

Shotgmi  po waders  dilTer  considerably  from  rifle  powders.  The 
shotgun  IS  distinguished  from  the  rifle  not  only  in  not  having  a rifled 
bore,  but  also  in  being  usually  of  considerably  greater  caliber.  To 
produce  a weapon  easy  to  handle,  it  is  necessary  to  make  the  forward 
portion  of  the  barrel  very  light.  Therefore,  there  must  be  hut  little 
pressure  except  near  the  breech.  Furthermore,  distribution  of  the  shot 
in  a uniform  pattern  seems  to  require  that  comparatively  lirric  pressure 
he  exerted  on  the  shot  in  the  ft>r\vard  portion  of  rhe  barrel.  For  these 
reasons  shotgun  powders  nuiM  bum  m<trc  rapidls  ilun  rifle*  ptiM'ders. 
and  therefore  there  tnusi  be  more  surface  exposed. 

In  the  black  powder  days,  the  standard  shotgun  load  was  three 
ilrao»s  weight,  or  8:  grain.s  of  black  pow'der.  This  was  always  loaded 
by  measure  instead  of  by  weight.  The  first  smokeless  powders  de 
velopcd  for  .shotguns  w'crc  called  “bulk*'  powders,  because  they  could 
be  loaded  bulk  for  bulk  with  black  powder,  using  the  same  three 
dram  charge  cup.  Later  on  a different  rvpc  of  shotgun  powder  was 
deveinped,  W'hich  was  much  more  powerful,  and  the  nirec  dram  meas- 
ure could  not  be  used  for  them;  a very  few  grains,  sav  24  m to  grains 
of  these  “dense”  powders  wcmld  give  Hit  same  vcf<K’ity  «is  a three 
drain  measure  of  black  or  bulk  snuikelcss.  'The  loads  of  these  modem 
dense  pow'ders  arc  still  i|  noted  In  drams,  bur  rhev  are  actual  I \*  “dram 
oquiva ferns”,  or  “equivalent  drams",  and  iK’ar  no  relation  to  actual 
dram  weights  or  co  dram  measures. 

The  first  successful  bulk  powder  was  kmiwn  as  Schidt^c,  after  the 
inventor,  Captain  E.  Schultze  of  the  Prussian  Artillery.  It  was  made 
from  nit ro 'lignin,  or  nitrated  wood  pulp,  mixed  with  nitrates  of 
barium  and  potassium. 

Modern  dense  shotgun  powders  arc  of  both  the  nitroglycerine  and 
the  straight  nitrocellulose  types.  Well  known  brands  arc  Hercules 
Red  Dot  and  du  Pont  Oval. 

Se?nt~S?fiokeJess  Po^xders,  Lesmok  Po'wder 

Besides  the  good  old  fashioned  black  powder,  and  the  modern 
smokeless  types,  there  was  for  years  an  intermediate  type  known  as 
semi-smokeless,  which  was  a mixture  of  black  and  smokeless. 


HATCHm’e;  N<irK»iOOK 


bihu((/c  powder,  One  of  ihc  e.irlies(  sucli’^^^ul  ••n»nkeJess  p.mder^.  It  is  of 
(he  type  called  "bnlk”  powder,  and  is  made  of  nitraied  wood  pulp  (or  Vitro 
Lignin), 


NotI'.s  on  CiiTKPo\vni>R 


319 

l,csmok  powder,  so  mucU  used  in  the  .22  caliber  niacdi  tarr ridges 
of  a few  years  back  was  a mixture  of  guncotton  and  black  powder. 
It  was  extremely  accurate  in  .22  caliber  loads  while  it  gave  imich 
more  smoke  and  fouling  than  the  modern  smokeless  loads,  the  fouling 
was  of  such  a nature  that  it  did  not  cake  or  harden  in  rhe  barrel,  and 
tiring  did  not  have  to  be  interrupted  fcjr  cleaning,  as  it  did  with 
straight  black  powder. 

In  rhe  days  before  the  advent  of  the  non-corrosive  primers,  the 
Lesjuok  loads  were  much  less  corrosi\'c  than  were  the  straight  smok- 
Igss  loads,  as  rhe  powder  charges  were  bulkier,  and  tended  to  carry 
away  more  of  the  primer  residue.  However,  after  the  non-corrosive 
primers  came  into  general  use  in  .22  caliber  ammunition,  the  tables 
were  turned,  and  the  potassium  salts  left  by  the  l>iarU  powder  ccmi- 
ponent  of  the  Lcsinok  powder  made  it  ncccssaiy  co  clean  rhe  bore 
soon  after  tiring,  regardless  of  the  kind  of  primer  used. 

One  of  the  great  dlsatl vantages  of  Lrsmok  powder  was  the  extreme 
hazard  to  life  involved  in  its  manufacture.  For  this  and  other  reasons 
it  has  gradually  fallen  into  disuse.  Ac  this  writing,  Fcl)riiaiy  *947*  ^ 
lot  of  Lesmok  loaded  .22  caliber  cartridges  has  rcccnrlv  been  com- 
pleted by  Winchester,  but  it  is  said  that  no  more  will  he  made. 

Anodter  powder  of  the  same  general  type  thar  was  formerly  very 
popular  hut  is  now  no  longer  made  was  King  s Scmi-Sniolxclcs>. 

Bail  Powder 

A dcvclopincnr  of  the  Western  Cartridge  (>>mpany  \s  hich  was  of 

frear  service  during  World  War  M was  what  is  known  as  Ball 
owder. 

As  has  already  been  seated  the  ordinary  tubular  grain  ride  or  pistol 
powder  is  made  of  a paste  or  “colloid’*  which  Is  sc^ucczcd  through 
what  is  known  as  a “macaroni  press”.  This  produces  tubes  of  powcler 
which  are  cue  to  length  by  revolving  knives  as  the  tubes  come  through 
the  press  dies.  After  being  extruded  and  cut  off,  the  grains  must  then 
be  dried. 

The  follow  ing  brief  description  of  the  manufiiciure  i*f  Hall  Powder 
W'as  written  bv  Lt.  Commander  Edwards  Brown,  of  the  NR  A Tech- 
nical Staff,  who  before  lie  was  called  t(i  active  dufv  in  194c  was  a 
pi*oducrion  engineer  in  the  Sniokcless  Powder  & l“bgh  Explosives 
Plant  of  rhe  Western  Cartridge  Co. 

The  Western  Cartridge  Company,  now  a division  of  rhe  Olin 
! Industries  Inc.,  has  developed  an  unique  process  for  rhe  manvifacturc 
of  smokeless  powder  having  individual  grains  in  rhe  form  of  little 
' round  balls.  The  basic  material,  nitro-rclhilose,  is  the  same  as  char 
I used  in  the  older  and  b error  knoxvn  extrusion  process.  The  process, 
however,  offers  one  distincr  economical  advantage,  rhe  nitrocellulose 
can  be  obtained  either  from  nexviv  nitrated  material  or  from  surplus 
cannon  or  small  arms  powder. 


HmCJUK'*  \oiMUN»k 


I.esmok  puwdcf,  popul^i  in  .22  lalibcj  rifie  and  pi>(ol  lactcidges  before  the 
.idveot  of  the  ocMi'Corrosive  primer,  li  U i mixture  of  percent  black  powder 

and  15  percent  guncotton. 


NcriKs  os  Gi'npowukk 


This  new  process  is  also  a relarivcly  safe  one  because  the  powder  is 
wet  from  the  beginning  of  the  process  until  tlie  finished  powder  grains 
are  dried.  This  makes  possible  another  ccominucal  advantage  in  chat 
the  nitrocellulose  can  be  pumped  as  a water  sliirrv  through  pipe  lines 
from  one  operation  to  another.  Trucking  is  thereby  eliminated  and 
handling  costs  arc  cut  lo  a minimum.  Processing  and  handling  there- 
fore amounts  to  a valve  Cuming  operation  under  the  watchful  eve 
of  technically  trained  supervisors  ami  the  control  laboratory. 

Lee’s  assume  that  Western  is  going  to  produce  linishcd  powder 
from  a blend  of  fibrous  guncotton  and  cannon  powder  and  we  will 
briefly  follow  the  process  from  beginning  to  end.  The  first  step  taken 
is  to  pump  the  old  powder,  together  with  water,  from  ihg  stt>rage 
tanks  through  a pipeline  to  the  beater  house.  Here  it  is  pumped  to  a 
hammer  mill  which  beats  the  powder  into  fine  particles.  The  fine 
particles,  suspended  in  water,  which  emerge  from  tlic  mill  makes  a 
slurry  which  resembles  mud  and  it  is  iisually  referred  to  as  such. 

The  slurrj'  is  piped  to  a large  storage  cub  where  the  proper 
quantity  of  guncotton  is  added  and  from  whence  it  is  pumped  through 
a long  pipeline  into  a large  jacketed  still  in  the  hardening  house. 

Chalk  is  then  added  to  the  still  to  counteract  the  free  acids  present 
in  the  old  powder.  These  acids  are  either  entrapped  during  the 
nitration  of  new  nitrocellulose  or  have  been  formed  in  ilie  old 
powder  during  its  storage  over  a period  of  years  and  may  be  the 
reason  for  its  having  been  declared  unserviceable.  As  snjokcless  powder 
decojii poses  it  forms  oxides  of  nitrogen  which  change  to  nitric  acid 
and  make  the  powder  dangerous  in  a drv  condition.  The  Western 
process  counteracts  these  acid.s  in  the  early  stages  of  ball  powder  manu- 
facture by  completely  dissolving  rhe  nitrocellulose  in  a solvent  and 
washing  this  lacquer  with  chalk  water  to  nCutra!i7.c  the  acid. 

A volatile  solvent,  erhyl  acctacc,  is  blown  through  a pipeline,  from 
an  outside  storage  rank,  into  the  still  with  the  slurry.  Uiphenylaminc 
is  also  pur  into  tiie  still  with  the  solvent  and  this  makes  the  future 
ball  powder  stable  for  years  to  come  because  diphenybminc  and  chalk 
react  with  the  oxides  of  nitrogen  forming  a harmless  chemical.  The 
solvent  dissolves  the  nitrocellulose  and  a pliable  lacquer  is  thus  formed. 
Large  paddles  in  the  still  arc  turned  on  to  agitate  the  lacquer  and  break 
it  up  into  small  particles.  The  still,  by  means  of  hot  water  flowing 
through  the  jacket,  is  heated  ro  facilitate  this  process. 

A protective  colloid  which  has  been  injected  into  the  still  keeps 
the  small  particles  of  nitrocellulose  lacquer  from  going  back  together 
again.  The  agitation  is  coiiiinucd  until  the  particles  of  lacquer  become 
spherical  in  shape.  As  soon  as  the  grains  are  of  the  desired  size  and 
shape,  the  ethyl  acetate  is  distilled  out  of  the  particles  into  a con- 
denser where  ihe  solvent  is  recovered.  When  the  ethyl  acetate  is  all 
driven  off  the  small  spherical  particles  arc  left  very'  hard. 


If! 


* 


fmcrior  ballistic  curv«$  for  the  1903  U.  $.  Rifle,  cal.  30.  Cartridge  was  loaded  with  130  graia  flat  base  bullet^ 
Ml90<i,  with  approximately  50  graios  of  Pyro  D.  G.  Powder,  giving  a muzzle  velocity  of  2700  feet  per  second.  Note 
that  ihe  travel  of  the  Injllet  from  the  start  of  Its  motitm  uocti  it  leaves  the  muzzle  requires  only  .00098  second;  the 
pressure  of  the  powder  gas  at  exit  is  approximately  7OU0  lbs;  and  that  cutting  7 inches  olf  the  end  of  the  barrel  would 
reduce  the  velocity  only  200  feet  per  second. 


Haiciikk's  N<irri!4K)K 


thouM94  Pooads  p«r  1 


ia  Barrel 

Curves  showing  pressure  versus  travel  ead  velocity  versus  travel  for  the  cart- 
ridge, ball,  caliber  .$0,  M 2.  Charge,  53  Crains  IMIt  4676,  Army  Lot  2006. 


Notes  ok  Gunhuwdef 


Pressure  in 


-1  A i W I J * * ' * * I > * r 

1 2 3 V 5 6 7 8 9 10  11  12  13  Uj  15  16  17 


Travel  in  Inches 

Cufv«$  showing  pressure  plotted  against  travel,  and  velodcy  against  travel  for  the  cartridge,  baJlj  carbine,  caliber  .30 
M 1.  Composite  of  10  round»i.  Charge,  12.4  grains  Hercules  Flake. 


Velocity  in  hundred  feet/second 


Nai>a  ON  Gunp*)wi)i:r 


325 

Sodium  sulphate  (salt)  is  put  into  tlic  still  to  aid  in  removing  the 
water  remaining  in  the  otherwise  solid  halls.  The  fresh  water  in  the 
balls  passes  through  the  surface  of  the  hall  into  the  salt,  i'hc  process 
by  which  this  is  ncc<miplished  is  known  as  os7ftosis.  After  the  balls  of 
powder  arc  dewatered  the  salt  water  in  which  they  arc  resting  is 
exchanged  f(»r  fresh  water  and  the  resulting  slurry  is  pumped  to  the 
screen  house  where  the  various  sizes  of  balls  are  segregated  as  to 
maximum  and  minimum  diameters  through  rotar^^  screens.  TTie  various 
segregated  sizes  or  cuts  flow  from  the  screens  into  separate  storage 
tanks  designated  for  each  particular  grain  size. 

At  this  point  the  ballistic  laboratory  hccnnics  vitally  interested  in 
the  halls  because  the  ballisck'  charactcrisrics  of  the  powder  are  par- 
rially  determined  i)v  the  si/e  of  the  individual  grains,  KA-ery thing  else 
being  eijual  the  smaller  diameter  grains  result  in  a faster  burning 
powder.  This  is  by  no  means  the  only  fact<»r  in  controlling  ballistic 
characteristics,  as  will  he  learned  later. 

Now  chat  the  balls  of  p>\vder  arc  scgrcgaicd  as  to  S174  and  scored 
under  water  in  varioas  large  wooden  tubs  assume  that  the 
ballisric  labfiratory  wants  to  make  a particular  |x»wcier  to  meet  pro- 
duction needs  for  a certain  cartridge.  From  rests  of  previous  hatches 
of  ball  powder  the  “lab”  knows  which  si/c  grain  conies  closest  to 
meeting  requirements.  'I'he  size  designated  is  accordingly  pumped 
from  Che  storage  tubs  through  a pi|>elinc  into  a large  jacketed  still 
in  the  coating  house. 

Here  two  coating  operations  are  carried  <»ut  in  the  same  srill,  The 
first  coating  is  nitroglycerine  and  the  second  k a deterrent  coaling, 
Both  of  these  coatings  arc  important  factor.s  in  controlling  the  final 
ballistic  characteristics  of  the  powder.  The  nitroglycerine  raises  the 
potential  or  total  energy  in  the  grain.  The  deterrent  delays  liie  burn- 
ing on  the  surface  to  provhlc  a progressive  burning  jwwder  in  spite 
of  the  ball  shape  which  would  <ithcr\visc  produce  “degressive" 
burning. 

After  the  charge  of  ball  powder  is  pumped  into  rhe  roaring  still, 
nitroglycerine  is  blown  from  an  outside  storage,  through  a pipeline, 
into  the  still.  This  is  iior  pure  nitrogiveerine  but  it  is  mixed  with 
a solvent.  The  solvent  serves  to  desensitize  riie  nitroglycerine  some- 
what, CO  make  it  safer  during  transportation  to  the  plant  and  during 
scurage.  The  contents  of  the  still  arc  agitated  by  large  motor  driven 
paddles  to  disperse  the  nitroglycerine  throughout  the  water  in  small 
droplets;,  forming  an  emulsion.  The  still  Is  heated  slightly  and  the 
solvent  together  with  the  nitroglycerine  enters  the  grains. 

After  the  nitroglycerine  has  impr^naced  the  grain  the  solvent  is 
driven  off  by  further  heating  of  the  sdll.  Providing  the  ensuing  heat 
treatment  is  properly  controlled,  the  deterrent  coating  will  penetrate 
the  surface  of  the  grain  only  to  the  proper  depth.  When  the  deterrent 


NoifjiuoK 


326 

uoacing  has  penetrated  the  surface  of  ihe  grain  the  remainder  of  the 
solvent  is  driven  off  and  the  individual  balls  arc  again  left  hard. 

The  unique  pan  of  the  ball  |X)wder  process  is  now  complete  and 
the  powder,  still  in  a water  .slurry.  Is  puin}>cd  to  a centrifuge  or  an 
Oliver  filter  to  remove  the  bulk  of  the  water.  The  }>owder,  no  longer 
in  a slurry,  muse  now*  be  damped  into  containers  and  hauled  to  the 
drier  where  all  but  a very  small  percentage  of  the  water  and  solvents 
are  removed  from  the  grain.  Western  has  been  drying  by  infrared  heat, 
a thin  layer  of  the  grains  being  fed  from  a )v»pper  onto  n continuous 
belt  which  passes  under  the  lamps. 

The  next  step  is  to  transpcin  the  dry  powder  10  a small  house 
where  it  is  tumbled  with  graphite  in  a large  doughnut  shaped  c(m 
tainer  called  a .sweetie  barrel.  This  gives  the  powder  its  black  ap 
pcarance.  Since  graphite  L>  .a  conductor  of  elwcricity  it  prevents  static 
dectricit)'  from  building  up  in  the  powder  on  subsequent  nperarions, 
Aliliougli  the  powder  was  W'et  screened  to  .size  ic  i>  now  dry  scrcoicd 
for  final  diminarii»n  of  any  grains  which  arc  above  the  mavimnm  and 
below  the  minimum  diameter  for  the  batch  speciticacion. 

After  the  screening  <>)>ernriun  the  ballistic  laboratory  takes  a sample 
of  the  batch  to  determine  its  ballistic  characcciistics.  Ii  is  seldom 
char  a hiUch  performs  CTjactly  as  desired.  As  in  the  manufacture  of 
mo^r  products,  chcre  will  be  a slight  vuriarion  in  production  units  in 
spite  of  precise  control  methods.  The  ballistic  expert  is  sirisHeJ,  how- 
ever, if  the  resnir.s  are  reasonably  dose  to  his  rcquiicmeiiTs.  I Ic  has  a 
record  of  results  of  other  batches  oi  the  ssmic  grain  size  which  arc 
in  magazine  storage.  With  his  batch  dura  l>efoix‘  him  he  cait  make  up  a 
combination  of  these  batches  which,  blended  logerher,  will  give 
him  optimum  results.  He  then  furnishes  instruct  inns  to  the  blender 
crew  letting  them  know  just  how  many  pounds  of  eacii  batch  shtjuld 
be  blended  together  to  make  up  the  finished  lot  of  ptiw  Jci. 

Since  ic  is  not  possible  to  control  the  hardening  operation  to  produce 
any  one  particular  grain  size  there  is  of  course  the  ipjcstion  of  how 
to  balance  the  production  of  the  powder  line  to  meet  ammuniiinu 
loading  requiieineiiR.  it  is  usually  found  that  there  is  a greater  need 
for  the  fine  grain  than  there  is  for  the  coarse  grain.  This  could  be 
taken  care  of  by  dumping  the  larger  sizes  from  the  screening  opera- 
tion back  in  the  hardening  still  and  proecisins^  it  t^ver  again.  This 
would  be  an  expensive  wav  of  gettinif  the  finer  grain  powder.  The 
prol)lem  is  acmally  .solved  by  running  the  larger  grain  ptjwder,  in  a 
water  slurry,  through  rolls  very  much  like  those  which  you  would 
see  in  a brass  or  .steel  mill.  These  rolls  flatten  out  the  grains  which 
happens  to  make  them  faster  burning.  When  rolling  is  called  for  it  is 
done  after  the  coating  operation  and  before  drviiig.  By  means  of 
this  rolLng  procedure  it  is  therefore  possible  to  giv’e  the  large  grain 
powder  ballistic  characterjsrics  similar  to  the  small  grain  powder.  This 


OF  TEMFEHATUAE  F 


M 


Notes  on  C»unk>wi»ek 


PR£SSU((E  IN  THOUSAND  LBS. 


328 


1 I VICIlVJi's  No  I KBOUK 


■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 


10  SHOTS  lACH  OAUGC 


MAXIMUM  PRESSURE 


AIL  COPPERS  INITIALLY 


COMPRESSED  3SOOQ  LB 


SSSSggaaSSSSSgiSBsaiiiieeSBSi 


IMR  IU7  LOT  1492 


PRESSURES  TAKEN  IN 


<9 


12492^0 


aaaaaaaaaaaaaBBsaaaaaaaaaBaaa 


2460  BO  2SOO  20  40  60  BO  2600  20  40  60  BO  2700 

INSTRUMENTAL  VELOCITY  AT  78  FT. 

Cuivcs  showing  re U lion  between  pressure  and  velocity  for  one  lot  of  IMR 
powder. 


Notes  on  Gl'npou’deb 


329 

permits  enough  flexibility  to  make  a balanced  production  line  possible. 
Consequently  some  “ball  powder”  Is  ike  instead  of  spherical  in  its 
finished  form. 

Ball  powder  was  used  for  mach  of  the  enormous  production  of 
carbine  cartridges  made  during  the  World  War  II  and  was  made  the 
standard  powder  for  those  cartridges,  it  was  also  used  in  some  of  the 
pistol  cartridge  production.  In  addition  the  Western  Cartridge  Co. 
loaded  several  hundred  million  7.91  inm  cartridges  for  the  Chinese 
Government  with  ball  powder. 

Ac  this  time,  (1947),  Ball  Powder  Is  being  used  in  rifle,  pistol  and 
shotgun  cartridges,  and  cives  promise  of  having  a wide  and  increasing 
use  in  the  future. 

The  Use  of  Tin  in  Rifle  Pouders 

In  the  period  immediately  following  World  War  I,  the  question  of 
metal  fouling  had  not  been  solved,  and  the  rifle  shooter  was  con- 
stantly confronted  with  trouble  from  this  source. 

The  French,  whose  artillery  we  used  very  largely  in  that  war, 
were  known  to  place  metallic  tinfoil  in  with  the  powder  charges 
used  for  field  guns,  in  order  to  prevent  the  depositing  of  copper 
fouling  from  the  metal  of  the  rotating  bands  on  the  shelH 

After  the  end  of  that  war,  the  du  Pont  organization  obtained 
patents  on  the  idea  of  incorporating  finely  powdered  metallic  tin  in 
the  colloid  from  which  the  gunpowder  was  made.  Popular  du  Pont 
powders  of  that  day  were  Nos.  15,  17,  etc.  When  tin  was  added 
CO  the  composition  of  one  of  these  pouters,  the  figure  Vz  was  added 
to  the  number  designating  the  powder.  Thus  powders  No.  15!^, 
No.  17!^,  etc,,  were  the  same  as  Nos.  17,  etc.,  except  that  they 
contained  a certain  percentage  of  tin.  The  first  of  these  powders 
that  wc  tried  in  a militar\^  loading  was  No.  i7Vj,  which  was  used  in 
rhe  National  Match  ammunition  of  1921  and  thereabouts.  This  was 
said  to  contain  4%  of  metallic  tin.  It  did  eliminate  the  old  metal 
fouling,  but  at  the  same  rime  it  introduced  another  kind,  though  a 
less  troublesome  one.  Tim  was  tin  fouling,  which  took  the  shape 
of  a dark  smoky  looking  deposit  inside  the  bore  of  the  rifle  near  the 
muzzle.  On  close  exaniinaiion,  tliis  appeared  to  consist  of  minute 
globules  of  metallic  tin  adhering  to  the  surface.  Evidently  the  tin 
in  the  powder  vaporized  under  the  terrific  heat  of  the  explosion,  then 
condensed  on  the  comparatively  cool  surface  near  the  muzzle,  after 
the  gas  had  also  been  cooled  somewhat  by  the  expansion  from  its 
first  high  pressure  to  a pressure  only  perhaps  one  tench  of  the  peak 
fig\ire. 

On  cleaning  a gun  so  afflicted,  it  would  be  found  chat  the  cloth 
patch  would  stick  rather  tightlv  on  the  rough  surface  where  the  tin 
had  been  deposited.  Once  this  fouling  had  occurred,  the  only  remedy 
was  to  scratch  it  our  with  a stiff  wire  brush,  w^hich  removed  it 
quickly  and  with  little  difficulty. 


PRtS$UR€  IN  THOUSANP  LBS. 


330 


Hatch FR*s  Notebook 


MEAN  PRESSURE  rD 

. t t i i » 4 

SHOTS  E 

b— i 

ACH  i 

B— 1 i 

SAUGE 

1 < 4 

IMR  1147  LOT  \49Z 


PRESSURES  Taken  in 


48  49  50  SI 

POWDER  CHARGE  IN  GRAINS 

Curves  showing  relation  between  pre^urc  and  |>owdcr  charge  w*ith  one  Jot  ol 
IMR  powder. 


Noras  ON  Gunpowder 


33^ 

As  a remedy,  the  percentage  of  tin  used  was  reduced,  first  to  2 14%, 
then  to  2%,  and  later  to  percent  or  less. 

Single  Base  Versus  Douhk  Base  Po'ivders 

For  many  years  there  has  been  more  less  of  a controversy  raging 
as  to  the  relative  merits  of  single  base  powders  as  compared  to  the 
double  base  varieties,  For  years  the  British  have  mainly  used 
Cordite,  which  is  a t)*pical  double  base  powder,  chough  this  has  been 
supplemented  in  times  of  war  ejneigency  by  du  Pont  powders. 

I he  old  W.  A.,  T.ightning,  and  Sharpshooter  powders  used  in  the 
Kiag  and  oLher  arms  of  that  day  proved  to  be  im desirably  erosive, 
and  chis  fact  was  largely  responsible  for  a shift  by  the  Army  to  a 
single  base  powder  as  the  st^andard  for  use  in  the  military  rifle. 

These  powders  had  some  30%  or  more  of  nitroglycerine  in  their 
compo.sirion,  and  as  it  was  found  that  the  higher  the  percentage  of 
nitroglycerine,  the  hotter  the  powder  and  the  more  erosive  it  was, 
the  indicated  remedy  was  to  lower  the  nitroglycerine  content. 

The  modern  HiVel  Powder,  which  for  years  has  enjdved  an  un- 
excelled reputation  for  accuracy,  especially  at  long  ranges  has  only 
about  20%  of  nitroglycerine,  and  is  little  more  erosive  than  the 
best  single  base  powders. 

The  Aimrumirion  Board  of  1923  made  a comparative  erosion  test 
between  the  HiVel  powder  used  in  one  of  the  National  Match  lots, 
and  the  1.  M,  R.  No.  17  which  was  used  in  the  other.  The  ten  barrels 
fired  with  HiVel  went  out  at  an  average  of  4700  rounds,  while  chose 
fired  with  No.  ly  lasted  but  very  little  longer,  or  3200  rounds, 

A direct  comparison  as  to  accuracy  between  the  single  base  and 
rlie  cUniljle  biuc  powders  was  had  in  a miniber  of  rhe  ammunition  tests 
held  in  rhe  years  following  World  War  I.  Figures  quoted  from  the 
tests  of  1924  and  1925  are  quoted  below: 


Year 

Bullet 

Powder 

Velocity 

at7«' 

f.s. 

Mean 
Pressure 
Ihs.sq,  in. 

MR. 

600  vds. 
* 

inches 

M.R. 

xrxx>yd. 

inches 

192+ 

1924 

1925 

1923 

171  grain 
9®  B.  T. 
Same 

172  grain 
9*  B.  T. 
Same 

47  gr.  HiVcl 

5J.5  I.M.R.  1145 
5J.2  IJM.R.  H47 

48,2  FliVel 
Lot  1488 

2701 

2697 

27164 

2694 

49*000 

48740 

49640 

44020 

2.260 

2.676 

2*303 

2.5:92 

5.685 

5.706 

57t 

6.887 

All  commercial  du  Pont  powders  arc  of  die  single  base  variety, 
while  those  made  by  the  Hercules  Powder  Co.  are  double  base.  The 
ball  powder  made  by  Western  Cartridge  Co.  is  also  of  a double  base 
composition. 


KNSTftUMENTAL  VELOCIIY 


isaBi 


!■■■ 

!■■■ 


nunHHi 


laiBi 


2600 


■■■■■■■I 

■■■■■■■I 

IBSBEB 


0£veLOf>MCNT  Of 


POWDER  CHARGES 


Ml 


IMR  ri47  LOT  1442 


2SS0 


EACH  VELOCITY  IS  THE 


MEAN  Of  10  SHOTS. 


aiBSBBBBBB 


Mill 


2500 


44  4S  44  47  48  44  $0  SI 

POWDER  CHARGE  IN  GRAINS. 

Curves  showing  re  I ui  ton  he  c ween  powder  charge  and  vcloeio  with  tw*n  lots  of  IMR  psmder. 


acxiHTLo^  s^a;4HDXV|-j 


Notes  on  Gunpowder 


333 


All  three  kinds,  that  is,  single  base,  the  regular  double  base,  and  the 
Ijall  powder  were  used  extensively  liv  the  Government  during  World 
War  n. 

As  to  small  arms,  the  cal.  .30  M2  cartridge  was  loaded  with  a 
single  base  powder  known  as  du  Pune  N’o.  4895.  The  charge  was 
adjusted  according  to  lor  to  give  2800  feet  per  second  muzzle  velocity 
to  the  150  grain  flat  base  bullet.  The  charge  varied,  according  to 
powder  lot,  from  about  49  grains  to  about  51.  The  average  pressure 
was  about  46,700  lbs. 

The  pistol  cartridges  were  loaded  with  either  du  Pont  p 4768,  or 
with  ball  powder;  thus  both  single  and  double  base  powders  were 
iLsed. 

The  carbine  used  two  kinds  of  powder,  both  double  base.  Tlicsc 
were  the  Hercules  C;d,  Ciarbine  Powder,  and  the  ball  pnuder. 

All  rocket  powder  used  in  the  War  was  of  the  double  base  variety, 
and  ic  is  interesting  to  note  that  o\sdng  to  the  high  potential  needed 
it  contained  a high  percentage  of  nitroglycerine;  something  like  40%. 

Poll'd er  for  Havdioaden 

Ac  the  present  writing  there  is  a rather  complete  line  of  powder 
available  for  the  handloader.  in  both  the  single  and  the  double  base 
varieties.  Some  of  these  arc: 


Vamp 

Type 

1 mended  Use. 

Hercules  HiVel 
Hercules  340c 
BiiUseyc 
Un  ique 

Double  Base 
Double  Baac 
Double  Base 
Double  Bose 

I.arge  capaciiv  cartridges. 

Small  & Medium  cti  pacify  carfridges. 
Pistol  Cartridges. 

Mid  range  rlBe  loads; 

super  vdocks  pjsinl  hmils. 

Smite  single  base  powders  available  arc: 

Powder 

Old  powder  it  is 
similar  to 

InreadeJ  use. 

I. MR.  42:7 
I. MR.  419^ 

I. MR.  No.  3031 

I.M.R.  No.  4320 

I.M.R.  No.  4064 

I.M.R.  1Z04 
r.M.R.  No.  25 
I.M.R.  No.  17^ 

I.M.R.  No.  1147 

I.M.R.  No.  15K 

For  small  capacity  cartridges. 

For  Mcdnim  Capacitv  Cartridges. 

For  medium  sporting  and  militaiy  car- 
tridges and  mid-range  Joads. 

For  large  capacity  sporting  and  military 
cairridges. 

For  Magnum  capacity  cartridges, 

XIV 


Gun  Corrosion  and  Ammunition 

Developments 

The  shooters  of  a generation  ago  really  had  their  troubles.  In  the 
first  place^  there  was  no  such  thing  as  a non-corrosive  primer  in 
rhis  country,  and  if  each  and  every  gun  were  not  cleaned  immediately 
after  shooting,  and  then  cleaned  auain  the  next  day,  it  was  sure  to 
he  ruined. 

Some  guns  were  sure  to  be  ruined  anyway,  no  inaticr  how  much 
they  were  cleaned,  for  etna  in  types  of  ammunition,  suck  as  ,22 
Short  Smokeless  had  so  much  primer  composition  in  proportion  to 
the  tiny  cliarge  of  powder  that  corrosion  seemed  to  get  a hold  before 
anytliing  could  be  ilonc  about  it,  and  in  spice  of  cvcryching  that 
could  be  done. 

In  fact,  the  knowing  shooter,  wlio  wanted  to  keep  his  gun  accurate, 
just  simply  didn't  use  .:2s  in  ^nokeles's  loads. 

Another  thorn  in  the  side  of  the  milinirv  rifle  shor  was  the  matter 
of  mccal  fouling,  which  came  in  in  1905  with  the  Springfield  rifle, 
'rhis  was  a gun  of  greater  power  than  its  predecessor  xUc  Kng,  and 
used  loads  of  much  greater  intensity.  Soon  after  the  Springfield  was 
introduced,  some  riflemen  found  it  impossible  to  keep  the  bores  of 
their  guns  looking  right.  Up  near  the  mn/.^le  there  would  be  what 
seemed  to  be  lumps  in  the  bore  which  no  amount  of  scrubbing 
could  get  out.  Ac  the  same  lime  the  accuracy  suffered. 

It  developed  that  these  lumps  were  cnpro-nickcl,  the  material  of 
the  bullet  jacket.  This  had  a neat  trick  of  adhering  to  the  metal 
of  the  bore  as  the  bullet  friction  developed  terrific  heat  between  the 
two  surfaces  of  bullet  and  l>orc.  Of  course,  as  soon  as  rhe  lump 
started  to  build,  it  formed  a n>ugh  spot  on  the  surface,  which  prompt- 
ly tore  off  more  of  the  next  jacket.  And  so  the  vicious  cycle 
progressed. 

In  those  clays,  there  was  just  one  way  in  which  the  high  powered 
military’  rifles  could  be  kept  shooting  with  any  semblance  of  accuracy, 
and  that  was  by  the  frciiucnt  and  regular  use  of  the  standard  Ord- 
nance Department  Metal  Fouling  Solution,  or  what  was  commonly 
called  “Ammonia  Dope”. 

The  Ordnance  Department  formula  for  Ammonia  Dope  was 


Ammonia  Persulphate  i ounce 

Ammonium  Carbonate  200  grains 

Stronger  Ammonia  Water  (28%)  6 ounces 

\Vater  4 ounces 


334 


Gu.V  COKKOSIU.N  AND  AMMUNITION  DkVELOPMKNTS 


335 

In  using  this  solution  the  brccch  of  the  gun  was  corked  up  and  a 
rubber  tube  was  slipped  over  the  muzzle,  so  that  when  the  barrel  was 
filled  the  muzzle  coold  be  entirely  covered  with  no  parr  of  the  meta! 
making  contact  with  the  solution  and  the  air  at  the  same  time.  If 
this  should  occur,  the  solution  would  attack  the  barrel  at  the  point 
where  it  came  in  contact  with  the  air,  and  the  barrel  w'onld  be 
ruined  in  a few  minutes. 

After  the  barrel  w’as  prepared  as  described  above,  it  was  filled  with 
solution  and  allowed  to  stand  about  twenty  minutes.  The  solution 
was  then  taken  one,  and  the  barrel  was  quickly  dried  and  oiled. 

The  solution  had  to  be  mixed  up  fresh  for  cverv  use,  as  stale  dope 
was  corrosive  to  the  steel.  Even  in  j'pitc  of  all  precautions,  the 
dope  would  sometimes  unaccountably  a track  the  steel  and  give  it  a 
sandblasted  appearance,  and  a rough  surface  inside,  which  mined  it 
Moreover,  if  any  of  the  solution  should  leak  past  the  cork  into  the 
breech  mechanism,  it  was  liable  to  remain  there  and  cause  serious 
rusting.' 

All  this,  of  course,  was  the  very  worst  kind  of  .a  nuisance,  and  it 
was  not  long  before  something  was  done  about  it.  A theory  was  de- 
veloped that  the  way  to  prevent  metal  fouling  was  to  provide  some 
kincl  of  lubricant  between  the  bullet  and  the  bore.  Various  kinds  of 
greases  and  vaselines,  with  and  without  graphite  and  other  ingredients 
were  tried.  These  really  did  help  the  metal  fouling  situation  a lot, 
and  in  the  period  just  before  and  after  World  War  J,  it  was  routine 
for  the  well  equipped  rifleman  to  carry  with  him  a small  tin  pill  box 
of  grease  called  Mobilubricant,  which  was  the  most  popular  one  for 
this  use.  The  bullet  was  dipped  into  this  just  before  each  shot. 

Just  W'hen  the  wheels  of  progress  seemed  to  be  going  smoothly, 
Col.  Whelen,  down  at  Frantford  Arsenal,  threw  in  a bucketful  of 
monkey  wrenches.  Some  trouble  W'a.s  had  at  the  National  Matches 
and  elsewhere  with  broken  bolt  lugs,  and  tests  made  at  Frankford 
disclosed  two  sad  and  frightening  facts:  i,  Grease  increased  the  bolr 
thrust  dangerously;  and,  2,  as  if  that  weren’t  enough,  grease  increased 
the  chamber  pressure  dangerously. 

When  the  gun  is  fired,  the  cartridge  is  driven  back  against  the  holt 
face  with  cl>e  force  of  the  powder  pressure,  resisted  by  the  friction  of 
the  brass  case  agaiiixt  the  chamber  walls.  Grease  in  the  chain  her 
takes  away  the  friction  of  the  case,  and  allows  the  entire  thrust  to 
come  into  the  boh  head.  Even  if  the  grease  were  put  on  to  the 
bullet  alone,  and  great  pains  were  taken  to  prevent  it  from  getting 
onto  the  case,  it  would  rub  off  the  bullet  onto  the  walls  of  the 
chamber,  whence  It  would  get  onto  the  case  anvway. 

As  to  pressures,  a test  was  made  with  1920  National  Match  Am- 
munition, which  gave  the  breech  pressure  of  the  dry  ammunition 
5^3J5»  while  with  the  bullet  and  neck  of  the  case  carefully  lubricated 
with  mselinc  the  prcsviire  averaged  59,000  lbs,  per  square  inch. 


Caliber  .30  pressure  piu|;e  in  use  at  Fraokford  Arsenal. 


Glk  Corrosion  and  Ammuniiion  Diai-loi'mims 


3J7 

With  the  1920  National  Alardi  Amnumicion  having  the  bullet  and 
ease  as  well  as  the  chamber  lubricated^  ilic  pressure  went  co  71,154 
lbs.  per  square  inch,  and  disastrously  wrecked  the  pressure  gage, 
which  was  considerably  heavier  and  stronger  than  an  • ordinary  rifle. 

This  was  what  was  likely  to  happen  if  grease  were  used  sparingly 
and  properly.  However,  human  nature  beit^  what  it  is,  the  grease 
was  often  used  liberally  and  carelessly.  After  all,  what's  a few  cents 
worth  of  cheap  grease  anyway?  Let's  jam  the  whole  clip  down  in 
the  grease  pot;  drop  it  on  the  ground,  wipe  pare  of  the  mixture  of 
sand  and  grease  on,  and  put  on  some  more  grease  Co  cover  up  the 
sand. 

So  the  Ordnance  DcpaiTiiienr  published  the  results  of  Clol.  Wheleil’s 
tests,  and  then  both  the  Army  Regulation-,  and  the  National  Match 
Rules  of  that  year  (1921)  forbade  the  use  of  grease. 

It  was  known  that  the  French,  in  order  co  prevent  depi>sits  of 
copper  from  the  rotating  band  of  their  artillery  projectiles  from 
smearing  onto  the  bore,  had  placed  strips  of  tinfoil  in  their  powder 
charges.  The  tin  seems  to  form  an  alloy  with  the  copper  that  m some 
WAV  prevents  it  from  sticking  to  the  bore.  .Mavhe  it  foriib  a low 
ijiciring  alloy,  and  pwmiits  it  co  be  melted  and  blown  away.  Anywav, 
ic  .stopped  die  copper  plating  of  the  bores. 

Col.  Whelen,  (then  Major)  who  was  making  ammunition  down 
there  ac  ITankford  Arsenal,  thought  this  over,  and  conceived  the  idea 
diac  it  might  he  possible  to  prevent  lumpy  metal  fouling  by  applying 
lin  to  the  bore  of  the  rifle,  and  the  way  he  did  it  was  to  tin  plate  the 
bullets.  A number  0/  experiments  chat  he  conducted  showed  that 
this  w'Ould  indeed  do  away  coinplcicly  with  the  Trnnl>lesomc  metal 
fouling. 

I was  ac  that  time  Works  .Manager  ac  Springfield  Amiory,  busily 
tiuning  out  the  National  Match  Rifles  for  the  J92J  Matches,  and 
naturally  awaited  with  great  impatience  the  first  Siunples  of  the 
actual  1921  National  Match  Ammunition,  so  that  sve  could  see  how' 
the  combination  of  rifle  and  ammunition  would  work. 

Finally  the  great  day  arrived,  and  we  received  the  fii*sr  sample  of 
die  1921  National  Match  Cartridges  from  Afajor  \Miclcn.  The  card 
chat  came  along  witli  it  gave  the  following  information: 

""Descriptio-fi.  Tliis  amiminirion,  known  as  1921  National  .\latdi 
Ammunition,'’  is  an  experimental  aDimunition  of  the  Caliber  .^o. 
Model  of  1906  type,  loaded  at  Frankford  Arsenal  far  use  in  ilu* 
National  Alatchcs  of  1921.  The  bullet  weichs  170  grains.  The  core 
is  a composition  of  30  pans  lead  and  i part  tin.  The  jacket  is  of 
cupro  nickel.  The  base  of  the  bullet  is  hollow,  to  prevent  the  lead 
core  from  extruding  and  making  the  base  untrue.  The  assembled 
bullet  measures  .3079"  in  diameter.  It  is  then  electrically  tin  plated 
so  as  to  give  a uniform  coating  of  tin  all  over  the  bullet  .0003"  thick, 
making  the  diameter  of  the  completed  bullet  .3085. 


H Aix  y I kr’s  N irrKB(x>K 


33^ 

The  case  has  a special  anneal  so  as  to  function  at  maximum  effi- 
ciency in  rifles.  The  ordinary  case  has  a fairly  soft  body  anneal  to 
enable  it  to  function  in  macl^e  guns  without  giving  ruptures  from 
the  excess  headspace  which  so  often  exists  in  tiiose  weapons.  This 
case  has  the  body  made  much  harder  so  as  to  extract  more  easily 
in  rapid  lire.  These  cases  with  the  ‘*Ilar4  Rifle  Anneal”  ate  dis- 
tinguished hy  the  letter  “R”  placed  after  the  year  of  manufacture  on 
the  head. 

Frankford  Arsenal  No.  70  primer  is  used  with  a charge  of  48.2  to 
48.8  grains  of  du  Pont  Ex- 1076  nitroccIluLose  progressive  burning 
powder  to  give  a muzzle  velocity  of  2700  feet  per  second  with  a 
breech  pressure  of  50,500  pounds  pec  square  inch. 

The  trajectory  of  this  ammunition  is  very  flat,  and  it  requires  the 
minimum  allow^ance  for  wind.  The  following  micrometer  elevations 
apply 

From  200  to  300  yards,  rake  2 minutes 

From  300  to  500  yards,  raise  7 minutes 

From  500  to  600  yards,  raise  5 minutes 

From  600  to  800  yards,  raise  9 minutes 

From  800  to  1000  yards,  raise  15  minutes 

Competitors  at  the  National  Matches  arc  particularly  cautioned 
against  the  use  of  grease  on  the  bullets.  Grease  will  cause  uneven 
velocities,  and  even  when  ic  is  used  carefully  is  liable  to  decrease  the 
accuracy  slightly.  But  more  imporranr,  the  use  of  grease  with  this 
ammunition  is  positively  dangerous.  It  alhiws  the  cartridge  case  to 
slide  to  the  rear  through  the  greased  chamber  more  readily,  and  thus 
increases  the  back  dirusc  on  the  bole  head.  Both  the  pressure  and 
the  velocity  of  tliis  ammunition  have  been  run  up  as  high  as  is  con- 
sistent witfi  safety.  If  grease  Is  used,  the  pressures  will  run  up  far 
above  the  safety  limit,  even  rurniing  as  high  as  75,000  pounds  per 
square  inch.  If  grease  should  be  used  k wUl  be  only  a question  of 
time  until  with  these  high  pressures  a case  with  the  head  slightly 
softer  than  ordinary  will  be  found  which  will  open  out  and  throw 
back  and  release  the  gas  to  the  rear,  demolishing  the  breech  mechan- 
ism and  possibly  injuring  the  firer.  Do  not  attempt  to  polish  the 
bullets  to  remove  tne  frosted  appearance.  The  ammunition  shoots 
more  accurately  with  these  frosted  bullets  than  when  they  are 
polished.^* 

A Question  an  Bullet  Puii 

When  we  got  this  new  ammunition,  w'e  immediately  started  dis- 
secting some  of  ic  to  see  what  we  could  find.  We  measured  and 
weighed  it  all  over,  then  started  to  pull  out  some  of  the  bullets  so 
wc  could  weigh  them  and  the  powder  charges.  But  here  we  ran  into 
a snag.  The  bullets  just  wouldn’t  poll.  We  had  a verv  nice  machine 
for  pulling  bullets  from  servdcc  cartridges  without  marring  the 


Gun  Corrosion  and  Ammunihon  l)Kvn.oi*MK.\Ts  339 

ballets;  this  machine  had  a dial  on  it  that  r^ad  the  buJIec  pull  in 
pounds  at  the  same  time. 

The  usual  bullet  pull  on  service  ammunition  at  that  time  was 
around  50  or  60  pounds,  but  the  first  bullet  of  the  new  lot  that  we 
pulled  ran  over  300  pounds,  and  some  ran  up  to  600  pounds  or  more. 


Dccail  of  pressure  gauge,  copper  crusher  type.  Ihe  cupper  cylinder  rests  on 
the  Steel  piston  shown  ac  (be  bmiom  of  the  yoke.  This  piston  fits  into  a hole 
that  >toes  down  into  (he  powder  chamber.  When  the  gun  is  llreil,  the  gas  pressure, 
actio g through  the  piston,  crushes  (he  copper  (ylindcr.  The  amouoi  of  shortening 
of  (he  cylinder  is  compared  lo  (be  dead  weight  required  to  shorten  a similar 
cylinder  a like  amount. 

1 .sat  down  right  a\vay  and  wrote  to  Col.  Wlielen,  telling  him  wliat 
we  liad  found,  and  asking  him  why  it  was,  and  if  it  would  cause  any 
trouble.  He  replied  that  apparently  die  tin  on  the  bullet  seemed  to 


An  imprnvcii  mnchinc  rest  for  ihe  Sprineficid  n'6e,  die  Wor>dworth  cradle,  inn 
re^l  froiri  a M^^nn  type  V- block. 


1 ^ , 

A 

i 

«• 

5 > 

Gun  Corrosion  akd  Ammukitiok  Df.vf.lopmkkts  . 341 

have  some  effccc  chat  might  be  described  as  a sort  of  cold  soldering; 
k more  or  less  glued  the  bullet  into  the  neck  of  the  case.  However, 
extensive  firings  had  resulted  in  no  trouble  from  this  cansc. 

Col.  Whelcn  was  absolutely  right.  When  shoe  dry,  this  was  a 
splendid  load,  wdeh  exceptional  accuracy.  However,  he  had  some- 
thing else  to  reckon  with,  and  that  was  the  face  chat  some  of  the 
National  Match  Competitors  were  of  the  type  w’ho  don’t  believe 
in  signs.  They  evidently  thought  that  w'aming  about  the  use  of  grease 
was  written  just  for  fun. 

I just  happened  to  be  in  on  rhe  .sequel  to  all  this.  I had  been  de- 
tailed as  Ordnance  Officer  for  the  National  Matches  of  that  year, 
and  was  standing  on  the  firing  line  during  one  of  the  first  matches, 
when  a rifle  just  a few  feet  to  my  left  had  a severe  blow -back,  w'hich 
splintered  the  stock,  bulged  the  magazine  well,  blew  off  the  extractor, 
locked  the  bolt  so  that  it  couldn’t  be  moved,  and  generally  wrecked 
things.  I just  stepped  over  and  noted  an  open  pill  box  of  grease 
licsidc  the  astonished  competitor,  so  I picked  up  the  block  of  cartridges 
he  had  been  using,  and  noted  that  they  were  well  daubed  with  grease. 

A little  reflection  showed  what  could  very  well  be  the  reason  for 
the  very  decided  reaction  of  this  ammunicion  to  grease  on  the  car- 
tridge. 

Smokeless  powder,  os  is  well  known  burns  quietly,  like  celluloid, 
if  it  is  ignited  in  small  quantities  in  the  open  air.  however,  it  is 
ignited  when  it  is  confined,  as  it  is  in  the  cartridge,  the  first  gas  and 
heat  that  arc  generated  cannot  e.scapc,  so  thev  cause  the  burning  to 
get  faster,  and  in  a hurry.  This  faster  burning  generates  more  gas 
and  heat,  which  makes  the  burning  even  more  violcnr,  and  wc  have 
an  explosion. 

Wicli  this  till  plated  ainiminicion,  with  the  bullet  practically  soldered 
in,  the  first  thing  chat  happened  when  the  powder  was  ignited  was 
that  the  initial  pressure  swelled  the  case  up,  and  expanded  the  neck, 
and  so  released  the  bullet  from  its  very  tight  seat,  so  it  could  move 
on  down  the  bore  and  give  more  room  for  the  first  rush  of  powder 
gas. 

However,  if  the  bullet  had  been  dipped  in  grease,  this  generally 
meant  that  the  neck  of  the  cartridge  wa.s  greasy  too.  The  space  be- 
tween the  neck  of  the  case  and  the  neck  of  the  chaiiiber  was  filled 
with  an  incompressible  substance,  aud  the  first  moderate  rise  in  pres- 
sure found  it  Jill  possible  to  expand  the  neck  and  release  the  bullet. 
Thus  the  p(»wder  was  strongly  confined  right  at  the  beginning  of  its 
ignition,  and  accordingly  the  pressure  rase  dkascrously. 

During  the  matches,  this  “Tin-Gm”  ammunition,  as  the  shooters 
called  it,  gave  exceptionally  fine  results,  and  many  new  records  were 
hung  up;  but  there  were  also  several  wrecked  rifles,  always  traced 
to  the  use  of  grease.  One  of  the  men  on  the  range  detail  brought  me 
a bullet  that  he  had  found  ou  the  range  that  had  fallen  there  with 


The  auchor  eesnne  National  Mateh  Ammunition  in  the  Woodworth  cradle — 1934. 


IIaTCMKRS  NuTEIJtMMC 


Gvn  Corkosion  and  Ammunition  DtVELOPMt.Nis  343 

the  neck  of  the  case  of  the  case  still  attached.  It  had  been  torn  off 
at  the  shoulder  and  had  beea  dr^ged  through  the  entire  length  of 
the  barrel,  becoming  mashed  down  to  bore  diameter  and  having 
the  rifling  engraved  on  it  during  the  process.  The  pressure  generated 
must  have  been  enormous. 

In  spite  of  the  several  blow-backs  occiuring  during  the  matches, 
no  one  was  hurt;  at  least,  not  to  amount  to  anvihing.  However,  the 
War  Deparemenr  decided  to  ban  the  use  of  this  tin-can  ammunition, 
and  all  of  it  remaining  on  hand  was  scrapped. 

Tin  in  the  Powder;  Luhaloy 

While  the  use  of  tin-plated  bullets  had  thus  received  a death  blow, 
the  use  of  tin  itself  for  the  purpose  of  preventing  metal  fouling  was 
by  no  means  dead.  I'here  were  two  other  and  safer  approaches,  and 
both  of  them  were  used  esctensively.  One  was  tl»c  actual  incorpora- 
tion of  tin  in  the  propellant  itself,  as  described  in  the  chapter  on 
Powder;  and  tiie  ocher  was  the  use  of  a bullet  jacket  metal  which 
contained  tin  as  a component  part  of  the  allov.  Such  a jacket  material 
was  introduced  around  1922  by  the  Western  Cartridge  Company 
under  the  trade  name  of  Lubaloy,  derived  from  the  claim  that  it 
was  a lubricating  alloy.  This  was  a compound  of  copper,  zinc  and  tin. 

New  Jacket  Materials 

Up  to  that  time  the  standard  bullet  jacket  material  had  been,  first, 
stcei,  coated  with  cupnvnickcl,  which  used  from  1H93  to  1902, 
then  solid  cu pro -nick el,  consisting  of  do%  copper  and  40%  nickel. 

Gilding  mecal,  consisting  of  90%  copper  and  10%  zinc,  was  a 
metal  that  was  .sometimes  used  for  bullet  lackets,  but  which  was  not 
considered  stiff  or  strong  enough  to  be  used  as  the  jacket  fur  the 
service  150  grain  flat  ba.se  bailee  having  a core  of  i pare  tin  to  30 
parts  lead.  Tlie  Western  Cartridge  Company's  Lubaloy  was  essen- 
tially gilding  mecal  containing  about  1%  tin.  The  same  alloy  was 
produced  by  Nobel  Industries  in  England  by  license  agreement  under 
the  name  Nobeloy, 

This  metal  turned  out  to  be  a very  good  jacket  material.  When  it 
was  used,  the  lumpy  metal  fouling  present  with  cupro-nickel  dis- 
appeared entirely.  It  first  came  prominently  to  public  notice  when 
the  Western  Cartridge  Company  won  the  competitive  test  for  the 
selection  of  the  Palma  Match  long  range  ammunition  for  the  1922 
matches.  The  winning  ammunition  was  called  Lubaloy-Palma,  and 
had  a 180  grain  flat  base  bullet  driven  by  46  grains  of  HiVel  powder 
at  a muzzle  velocity  of  2625  feet  per  second,  with  a mean  pressure 
of  46,800  pounds  per  square  inch.  The  average  measurements  of  the 
24  targets  shot  at  1000  yards  from  a Mann  rest  gave  a mean  radius 
of  5.69  inches.  The  angle  of  departure  for  1000  yards  wa^  38  minutes. 
The  Lubaloy  jacket  was  composed  of  90%  copper,  8%  zinc,  and 
2%  tin. 


Hatcher's  Notebook 


II  344 

I In  Che  National  Match  and  Pahiia  test  for  U)zzy  Frankford  Arsenal 
for  the  first  time  introduced  ammunitioa  with  gilding  metal  jackets. 

A report  of  the  test  in  Anns  and  the  Man  for  April  i,  192^, 
< states: 

I “Perhaps  the  most  important  and  outstanding  feature  of  the  encire 
^ test  is  that  gilding  metal  and  bronze  have  been  so  improved  in  pcocess 
' of  manufacture  that  they  can  now  be  utilized  as  materials  for  jackets 
I of  bullets  that  will  give  superior  accuracy,  and  that  these  jacket 
materials  have  the  great  advantage  of  depositing  no  lumpy  metal 
J fouling  ill  die  bore  of  the  rifle.  I’hcse  Lubaloy  and  gilding  metal 

' jackets  are  to  all  in c cuts  and  purposes  practicalfy  the  same,  both  in 

^ composition  and  result.*^ 

I Another  innovation  that  appeared  that  year  for  the  first  time  in 
the  standard  National  Match  animunitiun  w as  a tapered  base  or  boac- 
j tailed  bullet.  Both  this  year  and  the  previous  year  the  Western  Car- 

I t ridge  Company  had  entered  in  the  Palma  Match  tests  a bullet  with 

I a 4 degree  caper  on  the  base.  This  year  Frankford  Arsenal  eiucreci 
a 6 degree  boat  tailed  bullet  as  one  of  the  three  Iocs  submitted  for 
selection  as  the  type  for  the  National  Matches,  and  the  6 degree  boat 
tailed  bullet  was  cne  one  picked  as  a result  of  the  accuracy  test. 

The  National  March  Ammunition  to  be  made  bv  Frankford  Arsenal 
for  the  19::  National  Matches  was  dcscril>ed  as  follows: 

170  grain  6 degree  boat  tailed  gilding  metal  jacketed  bullet,  the 
jacket  material  being  90%  cupper  and  10%  zinc.  Loaded  w'ith 
No,  70  primer,  43  grains  of  HiVcl  powder,  to  a muzzle  velocity  of 
2685  feet  per  second  and  an  average  pressure  of  48,885  pounds  pci* 
square  inen.  Angle  of  departure  for  1000  yards,  37  !4  minutes.  IMean 
radius  at  600  yards  in  the  test,  3.16  inches. 

During  this  development.  Major  Towasend  Whelcn,  now'  Colonel, 
w'as  in  charge  of  the  Small  Arms  Department  at  Frankford  Arsenal, 
and  he  brought  to  both  the  design  and  manufacture  of  the  service 
cartridge  many  years  of  experience  in  all  phases  of  shooting,  together 
with  an  open  and  inquisiuve  mind,  and  a tremendous  capacity  for 
hard  work.  His  gilding  incial  jacket  spelled  the  end  of  the  metal 
fouling  bugbear. 

Barrel  Corrosloii 

Now  that  metal  fouling  had  gone  out  of  the  picture,  there  still 
remained  one  more  big  trouble  to  overcome,  and  that  was  the  in 
variable  tendency  of  every  rifle  and  pistol  barrel  to  rust  badly  ^^les^ 
it  were  cleaned  thoroughly  after  each  use. 

There  were  many  pet  theories  as  to  why  gim  barrels  corroded. 
One  of  the  most  obvious  and  the  most  widely  credited  was  the 
thou  gin  that  the  products  of  the  powder  comhiistion  left  an  acid  or 
corrosive  residue  in  the  bore  of  the  gun. 

Fven  the  Ordnance  Department  at  one  time  said  “Powder  foul* 
ing,  because  of  its  acid  reaction,  is  highly  corrosive  ” This  theory 


Gun  Corrosion  anu  Ammunition  DtvtLOi’MbMS 


345 

canie  in  with  smokeless  powder,  and  was  responsible  for  the  appear- 
ance of  a host  of  so-called  nirro-solvenis,  or  simply,  powder  solvcnt^j. 
Most  of  these  solvents  are  built  around  a base  of  amyl  acetate  or 
banana  oil.  Smokeless  powder,  in  burning,  is  likely  to  deposit  a 
gummy  substance  in  the  bore,  and  amyl  acetate  or  acetone  will  dis- 
solve this. 

One  such  solvent,  much  used  in  past  years  at  Springfield  Armory, 
and  in  practice  a most  excellent  gun  cleaner  and  preservative,  has 
the  following  formula: 

To  make  H gallon  take 
Amyl  Acetate,— 90  c.c.,  or  6 pans 
Acetone,— J85  c.c.,  or  19  pans. 

Spirit  of  Turpentine, -2%  cx.,  or  19  parts 
Sperm  011,-870  c,c,>  or  58  pans 
Pratt’s  Astral  OQ,-j9o  cx.,  or  a6  pans 

This  formula  was  invented  by  the  lace  Dr.  Hudson,  a famous  rifle 
shot  and  experimenter  of  a rjuarrer  of  a century  ago. 

The  Place’s  Astral  Oil  was  a very  highly  refined  and  acid  free 
kerosene  originally  produced  by  Pratt  & Co.,  of  Brooklyn,  and  after- 
wards taken  over  by  the  Standard  Oil  Co. 

This  Hudson’s  Cleaner  is  an  extremely  satisfactory  compound 
for  both  cleaning  and  preserving  firearms.  For  years  it  was  used 
extensively  by  the  experimeocal  Department  of  Springfield  Armory. 
I first  started  to  use  it  when  1 was  stationed  there,  and  the  only  care 
I ever  gave  my  guns  was  to  clean  them  very  promptly  with  this 
compound  jusc  ancr  shooting.  Unless  they  were  to  be  laid  up  for 
some  time  this  was  enough  to  keep  them  free  from  rust  or  corrosion, 
chough  in  theory  they  should  be  cleaned  again  die  next  day  then  be 
wiped  clean  and  lightly  greased. 

After-corrouan 

It  became  well  known  in  the  old  days  that  especially  in  a damp 
or  humid  climate,  a gun  would  often  show  rusting  in  the  bore  starr- 
ing several  days  after  it  had  liad  a choiT)ugh  cleaning.  To  account 
for  diis,  anodier  dicory  was  evolved,  which  was  called  the  Powder 
Gas  Occlusion  Theory,  or  the  Sweatmg-Ouc  theor\^ 

According  to  this  theory,  the  powder  gases  from  the  nitro  powders 
were  acid  in  reaction,  and  were  driven  by  pressure  into  the  pores 
of  the  metal  w'hile  the  barrel  was  heated.  It  was  supposed  chat  when 
the  barrel  cooled,  these  gases  slowly  diflfused,  and  on  corning  into 
contact  w'ith  the  air,  caused  corrosion  which  would  sometimes  con- 
rinue  over  long  periods  of  time,  in  spice  of,  and  following,  numerous 
cleanings.  The  advocates  of  this  theory  supposed  that  the  combustion 
of  smokeless  powder  must  produce  oxides  of  nitrogen.  The  theory 
was  apparently  confirmed  by  the  experience  of  many  riflemen  in 
having  corrosion  develop  after  careful  cleaning. 


346 


Haicwer’s  Notebook 


EUctrO’Chetmcal  Theory 

When  two  dissimilar  metals  touch,  there  is  a difference  of  electrical 
potential  between  them,  and  if  any  chemical  solution  comes  into 
contact  with  them,  a current  will  flow,  and  tlic  metal  which  is  the 
nfore  negative  of  the  two  will  be  corroded.  It  has  been  thought  chat 
the  metal  fonliiig  left  by  a bullet  would  form  an  electrical  couple 
with  the  metal  of  the  barrel,  and  that  in  rhe  presence  of  moisture, 
electrolysis  wotild  result,  and  corrode  the  steel.  However  no  evidence 
has  been  produced  to  show  that  this  action  takes  place  in  rifle 
barrels. 

Metal  Foulhtg 

It  was  also  suggested  chat  acid  residue  or  some  other  corroding 
agent  might  become  imprisoned  under  meui  fouling  in  ilic  bore  of 
the  rifle,  where  ordinary  cleaning  could  not  reach  it.  After  the  gun 
had  been  put  away  and  had  stood  for  a time,  it  was  supposed  5iac 
the  acid  would  work  itself  out  and  attack  the  stcci.  This  seemed  to 
be  a reasonable  explanation  for  after-corrosion.  The  fact  chat  after- 
corrosion  was  actually  prevented  by  doping  the  gun  seemed  to 
confirm  this  idea;  it  was  however  due  entirely  to  another  and  then 
unsuspected  reason  that  the  metal  fouling  .solution  proved  efficacious. 

The  Real  Cause  Discovered 

It  remained  for  Dr.  Wilbert  J.  Huff  of  the  Bureau  of  Mines  to 
discover  the  real  cause  of  firearms  corrosion  and  after-corrosion,  and 
rhe  explode  all  the  old  favorite  theories  mentioned  above*  During 
World  War  I,  in  1918,  the  Bureau  of  Mines,  at  the  request  of  the 
War  Department,  undertook  to  investigate  the  cause  of  after- 
corrosion  in  firearms,  and  the  work  was  assigned  to  Dr.  Huff,  of  the 
Biireau'.s  Research  Staff.  His  brilliant  work  on  this  project  was  rc 
ported  in  Technical  Papers  iBS— Corrosion  wtder  Oil  Fihns^  v^ith 
Special  Reference  to  the  Cause  and  Prevention  of  After-corrosion  in 
Firearms,  by  Wilbert  J.  Hu  IT,  publislied  by  the  Government  Printing 
Office,  1922;  price,  five  cems. 

Among  other  experiments,  Dr.  Huff  placed  fired  rifles  in  Iniiiiidors 
at  different  degrees  of  atmospheric  humidicy.  It  was  found  that  n 
humidity  of  less  than  approximately  50%  did  not  develop  corrosion  in 
fouled  rifle  barrels,  even  after  exposure  for  a number  of  days.  The 
two  rifles  used  in  this  experiment  were  then  exposed  to  100% 
humidity,  and  the  bores  immediately  developed  heavy  corrosion;  all 
other  mcral  parts  remaining  bright. 

Carrviiiy:  out  this  test  further,  sections  of  a barrel  which  had  been 
fired  were  exposed  at  various  humidities  at  a temperature  of  30®  C. 
and  corrosion  occurred  at  frum  68%  to  76%  luiiiiidity. 

Btillet  Jacket  Material  Foulhtg 

Bullets  were  driven  by  hand  through  unfired  barrels,  and  cupro- 
nickel filings  were  thrown  into  the  bores  which  were  then  exposed 


Gvx  Corrosion  and  Ammunition  DEVfcLOPMENis  347 

CO  100%  humidity  with  no  resultant  corrosion.  Evidently,  then,  metal 
fouling  is  inert  and  will  not  cause  corrosion. 

Acid  Gas  Diffusion 

Fired  rifles  were  induced  to  corrode  at  100%  humidity,  the  bores 
being  wiped  our  daily  umiJ  corrosion  ceased.  This  process  lasted  five 
days,  sliowiiig  that  if  gases  were  diffuang,  the  diffusion  was  completed 
in  thac  time  under  the  conditions  in  which  the  rifles  were  kept.  Ocher 
rifles  were  fired  and  kept  under  the  same  conditions,  but  in  less  chan 
50%  humidity,  and  did  not  corrode.  If  ga.ses  do  diffuse  and  this 
diffusion  was  complete  in  the  first  case  in  five  days,  it  is  reasonable 
to  suppose  thac  it  was  complete  in  the  second  lot  of  rifles  in  the 
same  time.  After  ten  days,  the  second  lot  of  rifles  were  exposed  to 
100%  humidity  and  immediately  corroded. 

If  corrosion  were  the  result  of  gases,  it  might  reasnnablv  be  ev' 
peered  to  occur  over  the  whole  of  the  bore  surface.  Sections  of  a 
corroded  barrel  show  thac  this  is  nor  the  case,  but  clearly  show  that 
corrosion  occurs  in  patches  W'hich  are  surrounded  by  clean  sections 
of  mecal. 

The  production  of  corrosive  acid  gases  by  the  burning  of  nitro- 
cellulose powders  under  high  pressure  is  not  indicated  by  chemical 
examination.  Carbon  dioxide  is  produced  but  lus  little  or  no  effect  in 
corroding  steel.  Hydrogen  and  carbon  monoxide  arc  also  formed, 
but  when  the  gases  arc  cooled  from  the  great  temperature  of  the  ex- 
plosion, 3900®  F,  the  presence  of  oxides  of  nitrogen  is  impossible. 

In  the  same  way,  it  can  be  shown  thac  the  formation  of  nitrogen 
oxides  from  the  primer  is  impossible,  while  it  can  be  clearly  demon- 
strated that  the  potassium  chlorate  of  the  primer  loses  oxygen  and 
gives  chloride,  the  salt. 

Other  examples  can  be  brought  to  disprove  the  gas  diffusion  theory 
but  are  merely  an  accumulation  of  evidence  that  corrosion  is  not 
formed  from  this  cause. 

rherc  remains  the  possibility  that  some  surface  residue  from  the 
powder  or  primer  may  form  an  acid  in  accord  with  the  first  theory 
given. 

Experiments  were  conducted  along  this  line,  and  no  trace  of  acid 
could  be  found.  The  presence  of  acids  or  acid  gases  from  powder  or 
primer,  when  burned  under  pressure,  must  then  be  di-sbelieved. 

It  can  be  sho\vn,  however,  that  some  powders  burned  under  little 
or  no  pressure,  such  as  in  reduced  loads  or  blanks  may  produce  acid 
residue,  due  to  incomplete  combustion;  but  inasmuch  as  after-corrosion 
is  present  when  no  acid  is  formed,  this  cannot  be  the  primary  cause 
of  this  corrosion. 

Potassium  Chloride  Theory 

Dr.  Huff  knew  most  primers  contained  potassium  chlorate, 
and  when  the  primer  is  fired  a certain  amount  of  potassium  chloride 


Hatcuer*$  Notebook. 


J48 
* 

is  formed.  Potassium  chloride  is  a sale  very  much  of  the  same  general 
chemical  formula  and  bdiavlor  as  the  common  table  salt,  sodium 
chloride.  Potassium  chloride  attracts  moisture. 

It  is  well  known  by  every  one  that  wet  salt  placed  on  a steel 
surface  will  immediately  cause  rust.  From  a consideration  of  these 
facts,  Dr.  Huif  conceived  the  idea  that  it  m^ht  be  the  potassium 
chloride  that  was  causing  all  the  trouble.  To  test  out  this  theory  he 
made  up  a priming  mixture  of  silver  permanganate,  lead  sulpho- 
cyanide,  antimony  sulphide  and  T.  N.  and  loaded  some  service 
cartridges  with  these  primers. 

Two  lots  of  guns  were  first  carefully  made  chemically  clean,  and 
then  fouled  by  firing;  one  lot  with  the  cartridges  primed  with  the 
above  mixture,  and  the  other  lot  with  a straight  service  cartridge  and 
primer.  The  bores  were  coated  with  oil  and  exposed  in  a humidor 
to  100%  humidity  for  one  week.  The  specially  primed  rifles  did  not 
corrode,  while  those  fired  with  the  service  cartridge  corroded  heavily 
under  the  oil. 

This  was  indeed  a great  ray  of  light  on  this  hitherto  dark  subject. 
It  is  not  only  demonstrated  the  truth  of  Dr.  Huff’s  potassium  chloride 
theor}^  but  it  further  showed  that  oil  alone  is  not  capable  of  pre- 
venting after-corrosion  by  excluding  air  and  oxygen  from  the  salt. 

A further  experiment  consisted  of  the  application  of  chemically 
pure  potassium  chloride  to  sections  of  a barrel  which  had  never 
been  fired.  When  exposed  to  100%  humidity,  these  gave  identically 
the  same  results  as  the  fired  rifle  barrels. 

Adherenrs  of  the  old  theories  jnav  object  iliac  repeated  cleanings 
should  mechanically  remove  the  safe;  tliat  the  many  endorsements 
of  non-aqueous  nitro  solvents  can  not  all  be  in  error;  that  after- 
corrosion  in  dry  arid  regions  like  Arizona  are  not  explained,  and 
similar  doubts. 

These  objections  are  not  at  variance  with  the  facts  as  found  by 
the  Bureau  of  Mine.s.  Repeated  cleanings  may  not  retnove  every 
particle  of  salt.  jMkroscopic  examination  of  a barrel  shows  very  plainly 
the  deep  cool  wounds  and  fissures  in  its  surface.  Corrosion  results  in 
further  deepening  thc.se  pits  or  scars.  When  potassium  chloride  is 
deposited  over  the  bore  surfaces,  it  gets  into  these  tool  wounds  and 
scars,  and  no  amount  of  mechanical  cleaning  can  insure  its  entire 
removal. 

It  is  also  a fact  that  while  desert  regions  are  dry  in  the  daytime, 
nightfall  is  accompanied  by  a rapid  cooling  of  the  atmosphere  which 
i.s  frequently  great  enough  to  precipitate  dew.  Reports  from  the 
Weather  Bureau  Stations  in  the  arid  areas  of  Ai'izona,  Utah  and 
Nevada  are  to  the  effect  that  all  these  stations  had  observed  the 
formation  of  dew. 

The  gas  diffusion  or  ‘‘Sweating  Out”  theory  is  now  showm  up  in 
its  true  colors.  We  have  seen  that  humidities  of  over  50%  are  neces- 


Gun  Corrosion  and  Ammunition  Dfaf,u)pmk.m.s  349 

sary  co  induce  corrosion.  After  firing  and  mechanical  cleaning  and 
oiling,  some  period  of  time  may  elapse  before  this  humidity  point  is 
encountered,  and  this  is  particukrly  true  where  guns  are  kept 
indoors  and  in  artifically  heated  atmospheres.  Part  of  the  salt  has 
probably  been  removed  in  cleaning  and  the  remainder  rubbed  into 
the  cracks  and  fissures  of  the  bore  surface,  where  it  lurks,  a dangerous 
and  invisible  enemy. 

It  may  tlius  remain  inactive  until  a relatively  high  humidity  is 
again  encountered,  when  corro^on  sets  in.  This  may  be  weeks  or 
months  after  firing,  and  formerly,  when  ic  appeared,  its  presence  was 
hard  to  understand,  and  was  naturally  attributed  to  “sweating  our” 
of  gases  or  acid-powder  residue. 

It  is  also  true  that  a long  period  of  high  humidity  might  develop 
the  maximum  corrosion  in  a short  time.  The  experiments  cited  show 
that  at  100%  humidity,  the  maximum  corrosion  can  take  place  in  five 
days,  and  subsequent  cleanings  showed  that  nn  further  corrosion  took 
place.  la  ocher  words,  the  pocassuim  chloride  had  been  completely 
dissolved  in  that  time  by  the  water  vapor. 

This  period  of  five  days  is  of  course  not  constant  but  depends  on 
varying  conditions.  It  does  show,  however,  that  a barrel  may  cither 
corrode  or  “sweat  out”  on  several  different  occasions,  or  the  corrosion 
be  completed  at  once  or  over  a single  period;  and  that  the  mechanical 
removal  of  the  salt  is  not  the  sole  means  of  stopping  ic.  It  may  go  on 
until  the  last  of  the  salt  is  dissolved,  where  it  scops  itself  for  lack  of 
fuel  as  it  were.  A gun  cleaned  at  this  stage  would  not  show  any 
further  corrosion. 

This  pocassium  chloride,  being  almost  the  same  as  ordinary  salt,  can 
easily  be  dissolved  in  water  and  washed  away  where  it  will  do  no 
harm,  whereas  oil  wiU  not  dissolve  ic  and  will  have  no  effect  on  it. 

Water  as  a cleaner 

The  Bureau  of  Mines  pointed  out  that  Potassium  Chloride,  the 
primary  cause  of  after- corrosion,  is  soluble  only  in  water  or  aqueous 
solutions.  Manifestly,  then  cleaning  the  barrel  with  water  will  dis- 
solve and  wash  away  the  salt,  The  Bureau  of  Mines  further  states,  how- 
ever, that  “Practical  riflemen  seem  to  have  a deep  seated  prejudice 
against  the  use  of  water  for  this  purpose.  . . 

This  is  readily  understandable,  fm*  the  water  must  be  thoroughly 
removed,  or  it  will  itself  cause  corrosion.  Tlic  diflicuhies  attending 
the  use  of  water  as  a cleaning  agent  are  apparent  when  one  considers 
solid  breech  rifles,  which  imist  be  cleaned  from  the  muzzle;  revolvers, 
where  the  cylinders  and  mechanism  present  numerous  cracks  and 
crevices;  extractor  slots  in  .22  caliber  rifles,  etc. 

Ic  can  now  been  seen  w'hy  the  ammonia  dope  was  so  effective  in 
preventing  after  corrosion.  Certainly  after  this  water)''  material 
itad  stood  in  the  bore  for  twenty  minutes,  there  would  be  no  salt 
left  undissolved. 


Hatcher’s  Notebook 


350 

As  a result  of  the  knowkdgc  gained  from  this  report,  the  standard 
method  of  cleaning  guns  fired  with  chlorate  or  so  called  “corrosive” 
primers  is  to  wash  out  the  bore  thoroughly  with  water » hot  if  available, 
then  dry  and  oil  it.  This  troublesome  procedure  is  a sure  cure  for 
• after-corrosion. 

Emulsions  and  Folarhed  Oils 

Soon  after  the  Huff  report  mode  the  shooting  world  primer-sak 
conscious,  there  appeared  on  the  market  a number  of  cleaners  de- 
signed to  take  advantage  of  the  natural  aversion  of  the  shooter  to 
the  use  of  water  for  cleaning  guns.  A very  popular  one  was  an 
emulsion  of  water  and  a red  oil,  probably  Turkey  Red  oil.  'I'hc  water 
dissolved  the  salt,  and  the  oil  left  a greasy  residue  which  stopped  the 
co^oiind  from  being  in  itself  a rust  producer,  as  is  water  alone. 

The  latest  cleaners  are  based  00  the  polarivscd  oil.  Tliis  is  an  oil 
combined  with  a substance  of  such  molecular  construction  that  it  has 
a strong  affinity  for  metal,  and  at  the  same  time  will  combine  readily 
with  both  oil  and  water.  As  it  is  explained  in  popular  language,  the 
molecules,  besides  having  a powerful  affiiiitv  for  metal,  have  “hooks” 
on  one  side  which  will  fit  and  take  hold  o^  the  water  molecules,  and 
on  the  other  side  they  have  “hooks”  which  will  fit  and  hold  the  oil 
molecules.  When  such  a polarized  oil  compound  is  placed  on  a wet 
metal  surface,  it  breaks  the  surface  tension  of  the  water  and  sinks 
right  down  through  it  to  the  metal  surface  and  clings  to  it, 

These  polarir.ed  oil  compounds  have  enough  water  in  their  make-up 
to  dissolve  the  primer  salt,  and  at  the  same  time  they  are  ^sufficiently 
oily  CO  retard  rusting. 

lanolin  Mixtures 

During  the  South  Pacific  Campaigns  of  World  War  II,  our  soldiers 
gained  the  impression  that  the  Japanese  had  a gun  cleaning  oil  that 
was  quite  superior  to  anything  that  we  had,  and  they  also  gained  the 
impression  that  this  preservative  contained  lanolin,  which  is  a grease 
extracted  from  wool.  Lanolin  has  the  property  of  mixing  with  water. 
In  ocher  words,  it  seems  to  have  some  at  least  of  the  properties  of  the 
polarized  oils  mentioned  above. 

Col.  Dwight  Garrison  of  the  Ordnance  Department  who  was  at 
the  time  serving  in  Australia,  undertook  to  test  and  analyze  the 
Japanese  gun  oil,  and  to  develop  one  for  our  own  use  which  would 
be  at  least  as  good  if  not  better.  He  arrived  at  a formula  which  as 
reported  by  him,  performs  exceptionally  w'cll.  This  is 


Dehydrated  Lanolin  15% 

Green  Petrolatum  35% 


Motor  Oil  SAJI,  No.  20  Heavy  (viscosity  at  70  dcg.=3o  S.A.F.)  50% 

From  the  amount  of  talk  about  lanolin  chat  was  heard  in  connection 
with  the  Japanese  oil,  one  might  conclude  that  its  virtues  in  this  field 
were  just  being  discovered;  but  this  is  evidently  not  so,  for  I find  in 


^LLET 


“020 

-010 



VdfO 

.030 

1 

1 

•02 

010  - 
rOlO 

ANVIL 

- 1 

1 

1. 


CHA8CE  OF  SMOKELESS 
PISTOL  POWDER  TO  OlVE 
S20i  25  FT  PER  .SEC. 
VELOCITY  AT  2si 
FEET  IN  PISTOL,  AUTO^ 
MATIC  CAL.45  MlSMAI 


SEAL,  CASE  VENT 
DISC 

CUP.  PRIMER 


THE  MOUTH  OF  THE 
CASE  MAY  BE  CRIMPED 
INTO  THE  BULLET. 


JACKET 


-SLUG 


Cafiridgc,  BalJ,  caJ.  .45,  M1911. 


I 


352 


Hatcher's  Notebook 


my  notebook  the  formula,  written  by  me  in  1920,  for  che  Fmnkford 
Arsenal  Nitro -solvent  Gun  Cleaner  No.  18.  The  formula  as  I re- 
corded ic  is 

Accujiic  

Kerosene  (Pract’.s  Astral  Oil)  

Spcmi  Oil  

Mineral  Spirits  (turpentine)  

To  every  800  cxr.  add  i$o  grains  uf  anliydrous  bnolin. 

Stir  up  the  lanolin  with  imneral  spirits  first,  add  acetone  last.  Per* 
fvjnic  with  citronella  if  desired. 

Oleic  Acid 

Another  substance  which  lias  been  used  in  gun  cleaners  and  which 
may  act  somewhat  the  same  as  lanolin  does  is  oleic  acid.  This  at  least 
seems  to  have  a definite  emulsifying  effect,  and  may  be  more  or  less  of 
a polarizer.  As  a Lieutenant  in  the  Arcilierv,  in  1911  I was  sucloned  in 
Florida,  where  the  hunting  was  very  good;  sometimes  full  sized  alli- 
gators would  come  up  from  the  nearby  bayou  into  my  back  yard. 

At  that  time  the  Remington  rcprescmaiivc  for  that  territory  was 
C.  B.  (^^Cardboard**)  Smith,  and  when  I obtained  from  him  a .25  and 
also  a .35  Remington  No.  9 Autoloading  Rifle,  he  advised  me  to 
use  Hoppe’s  Nitro-Solvent  No.  9 for  cleaning  them.  1 was  ouicc 
curious  as  to  the  composition  of  this  cleaner,  and  some  years  later 
had  an  opporcunicy  to  have  ic  and  a number  of  other  cleaners 
analyzed  in  connection  with  a study  of  gon  preservers.  My  noce- 
boolc  gives  it  the  following  probable  composition: 

Oleic  acid  

Ncuual  Saponifiable  oil  

Nicro-benzine  

T.ighc  Mineral  Oil,  such  as  kerosene 
Amyl  acetate  5 

The  percentages  are  approximate.  This  was  written  down  by  me 
some  2j  years  ago,  and  may  not  represent  the  Hoppe's  of  today. 

Soap 

A gun  preserver  w'hich  was  much  in  vogue  in  this  country  just 
after  World  War  1 was  a British  product  known  as  B.S.A.  Safei- 
Pastc.  The  initials  stand  for  the  maker,  the  well  known  firm  of  Bir- 
mingham Small  Arms  Company.  This  was  much  praised  and  recom- 
mended by  gun  editors  and  experts.  It  was  said  to  be  a good  safe  pre- 
venter of  corrosion,  and  a boon  to  the  lazy  man,  as  all  chat  was  neces- 
sary was  to  coat  che  bore  with  this  after  shooting  and  then  forget 
che  gun  until  the  next  time  it  was  wanted  for  shooting.  I can  testify 
from  personal  experience  with  this  product  that  it  was  cvcccdinsrtv 
effective.  Again  1 quote  the  approximate  probable  composition  of  a 
sample  of  25  years  ago  from  my  notebook.  It  was 


24% 

54% 


I pan 

I pare 
] pan 
1 pare 


Gun  Corrosion  and  Ammunition  Devkloi^ments 

Dry  s<iap,  soluble  in  alcohol 

Mineral  oil  

Water  and  Amyl  Alcohol  

Noncorrosive  i^Thners 

When  the  primer  was  definitely  identified  as  tlic  culprit  behind  die 
gun  corrosion  trouble,  it  was  only  natural  that  there  should  at  once 
arise  a great  bustle  of  activity  directed  towards  finding  a primer  that 
would  overcome  this  defect. 

Let’s  go  back  a few  years  intn  primer  history.  For  many  years 
after  the  first  metallic  cartridges  came  into  use,  all  primers  had  as  one 
of  their  principal  constituents  a very  sensitive  explosive  called  ful 
Miinatc  of  mercury,  and  in  addition,  they  had  more  or  less  potassium 
chlorate.  This  mixture  worked  all  right  with  black  powder,  which 
deposits  some  percent  of  its  weight  in  the  form  of  solids  when  ii 
burns.  This  large  amount  of  fouling  completely  masked,  diluted,  and 
washed  away  the  small  amount  of  solid  material  left  by  the  primer 
combustion. 

When  smokeless  powder  came  into  use,  the  picture  changed.  Tlw 
explosion  of  the  cartridge  left  the  bore  of  the  gun  and  the  inside  of 
the  cartridge  clean  and  nearly  free  from  fouling.  The  material  de- 
posited by  the  primer  combustion  had  a fine  clear  place  to  land. 

The  first  result  was  noted  by  the  hand  loaders.  In  those  days 
everyone  was  more  or  less  used  to  loading  his  own  charges  from  the 
powder  horn  and  shot  flask  which  hung  by  the  old  muzzle  loader 
that  stood  in  the  comer.  When  guns  came  into  use  that  had  nice 
expensive  brass  cartridge  cases  to  hold  the  charge,  what  was  more 
natural  than  to  reload  the  empty  ones;  especially  as  the  black  powder 
then  in  use  was  so  flexible  that  no  table  of  charges  was  necessary. 

As  a result,  handloading  was  almost  universal  in  the  days  of  rhe 
early  breech  loader.  When  smokeless  powder  came  into  use,  the 
handloadcrs  noted  with  dismav  that  the  brass  cases  cracked  after 
being  used  only  a ver\'  litrle.  Yhe  cause  of  this  cracking  was  finallv 
traced  by  the  Ordnance  De  par  linen  t to  the  mercury  deposited  from 
the  fulminate  ujicd  in  the  primer  composition. 

This  wai  described  by  the  Chief  of  Ordnance  in  his  report  for  the 
year  1897.  The  next  year  the  Ordnance  Department  started  loading 
the  service  Krag  cartridge  with  a non-mcrcuric  primer.  When  World 
War  I came,  the  standard  mixture  used  by  Frankford  Arsenal  and 
known  as  FH-42,  had  the  following  composition: 


Sulphur  11. 97% 

Potassium  Chlorate  47.2090 


Antimony  Sulphide  50.8^% 

This  mixture  superseded  rhe  former  H-48,  which  contained  ground 
glass,  thought  by  some  sliooters  to  injure  the  bore.  This  primer 


^ 1 

• 

Ifl 

Ib' 

[ 

4 

0AWUf''^9i^^9HSr  *' 

M 

"1^  "l>i 

* rs 

. 't 

Some  World  War  I bulUn 


Gun  Corrosion  and  Ammukition  Developmknts  355 

entirely  elimlaaceJ  the  ease  cracking  trouble,  anti  was  really  one  of 
the  most  satisfjiccory  ever  ased,  unril  an  unexpected,  and  at  the  time, 
not  II  nd  CIS  cue  kI,  incidenc  caused  its  sudden  abandonment. 

The  United  States  entered  the  First  World  War  in  April,  1917, 
and  the  production  of  Frankford  Arsenal  was  at  once  stopped  up  to 
several  times  what  it  had  ever  bc«i  before.  Then  in  May,  trouble 
began  with  misfires  in  the  Frankford  Service  Ammunition.  The 
trouble  was  so  serious  that  the  entire  aniniiinition  plant  was  shut 
down  right  when  they  needed  its  production  \voi*sc  than  they  had 
ever  needed  it  before.  The  best  chemises  and  engineers  available 
were  put  to  w'ork  to  discover  the  cause  of  the  misfires  and  the 
remedy,  but  in  the  meantime  months  of  production  were  being  lost, 
so  that  the  Ordnance  Department  suminarily  ordered  no  more  IT-48 
primers  made,  and  directed  Frankford  to  adopt  and  \ise  forthwith 
the  Winchester  Repeating  Arms  Company’s  primer,  35-NF  which  was 
then  giving  very  satisfactory  results. 

This  primer  mixture  had  the  following  composition: 


Potassium  CliJoraiv  • ^3% 

Antimony  Sulphide  17% 

LmU  SufpluJHiyanKte 

Tri-nitro ‘toluol  i'l.S.l.)  


After  its  adoption  by  Frankford  Arsenal  this  primer  became  known 
as  F.A.  No.  70,  and  has  been  used,  with  minor  modificarioiis,  ever 
since. 

The  trouble  with  the  old  sulphur  primer  was  afterwards  traced 
CO  the  overloading  of  the  primer  drying  houses  that  occurred  when 
production  was  stepped  up.  The  primers  were  loaded  w'ith  the  mix- 
ture in  a moist  eonaition,  and  the  loaded  cups  were  then  pur  in  the 
drying  houses  where  steam  heat  was  used  to  dry  them  out.  When 
the  drying  houses  were  overloaded,  the  presence  of  so  many  primers 
in  the  w'am^  room  produced  a condition  of  humidicv  in  the  air,  and 
the  primers  generated  sulpliuric  acid  from  the  action  of  the  moist  air 
Oil  the  sulphur  and  the  potassium  chlorate. 

Ac  this  time  a typical  rim  fire  primer  used  in  the  .2:  caliber  am- 
munition had  the  loUowing  composition  as  obtained  bv  chemical 
analysis  in  the  Frankford  Arsenal  Laboratory.  This  was  from  the 
United  States  Cartridge  Company  s “X.R.A.”  caliber  Outdoor 
type  cartridge,  loaded  with  Lesmok  powder. 


Potassium  Chlorate  4143% 

Antimony  Sulphide  9*55% 

Copper  Sulphocyanldc  4.70% 

Ground  Glass  ' 


The  average  weight  of  the  priming  in  this  .22  rim  fire  cartridge  was 
found  to  be  0.237  grain. 


Hatcuui  s NaixBOOK 


35^ 

The  American  ammunition  companies  and  the  shooters  too,  were 
apparently  quite  unconscious  of  any  trouble  from  the  priming  com- 
position until  Dr.  Huff  published  his  findings  in  1922.  But  evidently 
the  Germans  had  been  at  least  20  years  ahead  of  us  in  this  held,  for 
wc  find,  as  quoted  by  Major  J.  C.  Gray  of  the  Ordnance  Technical 
Staff  in  his  article  “Lighting  the  Fire"  in  the  Amer'xctm  Riflemm  for 
January  1926,  that  cJ>c  publication  Zeitschrift  fur  das  Gesampie 
Schiess-u?id  Sprengstofiu'trsen  for  March  15,  1914  states  “Attempts  to 
manufacture  a priming  composition  wUich  docs  not  cause  the  barrel 
CO  rust  were  begun  about  1900.’’  Also,  “The  first  rust -free  primers 
were  made  in  1901  by  the  Rheinkche-Westphalisdic  Sprengstoff 
A.  G.  in  1901.“ 

The  German  composition  contained  barium  nitrate  in  the  place 
of  potassium  chlorate,  tt^ether  with  some  picric  acid  to  strengthen 
the  mixture.  The  formula  was  as  follows: 


Fulminate  of  Mercury  39% 

Barium  Nitrate  41% 

Antimony  Sulphide  9^ 

Picric  Acid  

Ground  Glass  6% 


It  also  developed  that  the  Swiss  Army  had  been  using  a non- 
corrosive  primer  since  about  1911.  This  was  based  on  the  formula 
of  a Swiss  inventor  named  Ziegler.  The  Swiss  formula  was 


Fulminate  of  Mercury  40% 

Barium  Nitrate  25% 

Antimony  Sulphide  25% 

Barium  CarlKHiatc  6% 

Ground  Glass  4% 


The  barium  nitrate  replaced  the  potassium  chlorate,  and  the  barium 
carbonate  was  added,  probably  to  neutralize  the  acid  products  of 
combustion. 

As  far  as  I can  see,  there  was  no  attempt  made  on  the  part  of 
the  Germans  or  the  Swiss  to  keep  these  things  secret.  Apparently 
the  information  was  there  available  to  anyone  who  had  taken  the 
trouble  to  read  the  foreign  scientific  journals  and  to  realize  the  real 
significance  of  what  he  saw  there. 

As  a matter  of  fact,  it  was  quite  well  known  in  shooting  circles 
in  this  country  just  before  World  War  I that  the  Germans  had  been 
using  since  1911  what  was  known  as  the  Rostfrei  (rustfree)  primer 
in  at  least  one  brand  of  .22  caliber  rim  fire  ammunition.  However, 
not  much  notice  was  taken  of  it.  There  was  very  little  foreign  .22 
caliber  ammunition  sold  here,  and  though  a few  gun  editors  spoke 
of  it,  no  one  seemed  to  grasp  the  fact  that  a whole  new  idea  in  am- 
munition  had  been  laid  at  their  feet  until  Dr.  Huff’s  report  woke 
them  up. 


Gun  Corrosion  and  Ammunition  Devfjxipmf.kts 


357 


This  German  *‘R'*  primer  had  the  following  composition: 


['ulminace  of  Mercury  55% 

Antimony  Sulphide  11% 

BarKim  Peroxide  27% 

T^.T 7% 


It  will  be  noted  chat  there  was  no  chlorate  in  this  picture.  But 
when  attention  had  first  been  called  to  it,  cliere  were  rumors  that 
this  primer  was  very  erosive  on  gun  bores  on  account  of  a gritty 
hariuiji  carbonate  formed  during  the  combustion.  That  is  one  reason 
why  no  more  attention  was  paid  to  it  in  this  country. 

As  soon  as  the  Huff  report  was  released,  both  Frankford  Arsenal 
and  all  the  commercial  companies  woke  up  and  started  working  on 
the  development  of  a non-corrosive  primer.  The  first  to  place  a satis- 
factory mixture  on  the  market  was  Remington,  with  their  K1  can  bore 
primer.  This  was  the  development  of  Mr.  J.  E.  Burns,  a chemist  on 
the  Remington  staff.  This  came  on  the  market  in  1927*  and  was  fol- 
lowed in  short  order  by  other  brands  and  makes. 

All  of  these  early  primers,  like  the  German  ones,  contained  fulmi- 
nate of  mercury,  and  on  account  of  this  ingredient,  they  all  .suffered 
from  the  serious  disadvantage  of  short  life  in  storage. 

Frankford  Arsenal  made  a chemical  analysis  of  these  early  non- 
corrosive  priming  mixtures,  with  the  following  result: 


Remington 

Kleaniwe 

Western 

Winchester  Peters 
Suynicss  Rusdess 

Kulminatc  of  Murcurv  

44-40% 

40.79^f 

41  js6% 

38.66% 

Barium  Nitrate  

. . . . y>.$4% 

2603% 

9*95% 

. . a.20% 

S.11% 

c tB90 

Ground  Glass  

....  20^66% 

28.4)% 

> * • 4r  f w 

26.66% 

24*90% 

Undetermined  lead  ct)mpound 

25.91% 

Hinder  (gum,  etc.)  

, . . , . .2o9c 

,J3% 

.58% 

.56% 

I'hese  mixtures  all  tended  to  bectome  inscnsicive  and  to  suffer  from 
hangfircs  and  misfires  after  storage  for  a year  or  two,  especially  in 
a warm  dajiip  place.  This  was  due  to  the  action  of  the  fulminate  of 
mercury  which  they  contained.  This  lead  to  the  eventual  discovery 
of  various  substitutes  for  the  fulminate,  and  all  current  mixtures  are 
of  the  non-mercuric  type. 

Two  typical  non-mercuric  primer  compounds  arc  those  patented 
by  Edmund  Ritter  Von  Herz  and  Hans  Rathburg,  and  ac<|uired  from 
them  by  the  Remington  Arms  Company  shortly  after  the  introduction 
of  the  first  Kleanbore.  These  formulae  follow: 


Composition  No.  1 % % 


Guanyl  Nicro-amino-jjuanyl-tctraccnc  0.5  to  ij. 

Lead  Tri-nltro-resorcinate  20.  to  4?. 

Barium  Nitrate  jn.  to  50- 

Antimony  Sulphide  or  other  fuel  or  both,  as  e^.  Calcium 
Siliddc  10.  to  %o. 


Matcher’s  Noti£book 


358 

Oir:i]Hisicic>r>  No.  2 


Gaanyl  Nicro-Aniir\o-gi«nyl-ieiraccne  0.5  to  2 

Lead  Tri-nitro-resorcinatc  35.  to  40 

Barium  Nitrate  35.  to  42 

Lead  Peroxide  7.  to  (2 

Antimony  Sulphide  o.  to  5 

Calcium  Silicidc  0.  to  ta 

Glass  o.  to  3 


Naturally  die  Ordnance  Departnicnc  was  t^uiic  anxious  to  use  a 
non-corrosive  primer  in  the  service  ammunition,  and  a number  of 
experiments  to  this  end  were  made  at  Frankford  Arsenal,  but  the 
mixtures  tried  cither  did  not  give  good  ignition  or  else  failed  to  stand 
storage,  or  developed  some  other  disability. 

As  the  Swiss  were  using  a noncorrosivc  primer  in  their  regular 
service  ammunition,  there  seemed  no  good  reason  why  we  should 
not  do  the  same,  especially  as  we  knew  what  the  Swiss  composition 
was.  A study  of  samples  of  Swiss  ammunition  showed  that  the 
weight  of  rhe  primer  pellet  they  used  wa.s  considerably  greater  than 
rliHi  of  oui^.  We  were  using  al^ut  all  the  mixture  we  could  get  into 
the  primer  cup,  and  it  was  impossible  to  get  in  as  inudi  composition 
as  the  Swiss  used.  This  was  because  we  used  a primer  known  as  the 
Boxer  type,  having  the  anvil  of  the  primer  in  the  primer  cup  itself, 
while  the  European  nations  used  the  Berdan  primer,  in  which  there 
was  no  separate  anvil;  instead,  there  w*a$  a raised  section  of  metal  in 
the  bottom  of  the  primer  pocket  of  the  case  M'hich  acted  as  an  anvil. 

The  primer  with  the  Berdan  anvil,  integral  with  the  cartridge  case, 
allowed  more  room  for  an  increased  charge  of  mixture.  Moreover,  it 
gave  an  opportunity  for  more  direct  ignition  of  the  powder,  for  the 
flash  holes  lead  directly  from  the  primer  to  the  powder,  while  in'  our 
Boxer  type,  the  flash  hole  is  located  under  the  center  of  the  anvil. 
The  flash  has  to  go  through  some  cut  out  places  in  the  edge  of  the 
anvil,  then  come  back  to  the  center  and  go  down  the  flash  hole  to 
reach  the  powder.  Tn  other  words,  it  more  or  less  has  to  go  around 
a corner  to  gee  through  the  flash  hole. 

It  should  be  noted  that  the  Berdan  Primer  is  an  AmeriCcUi  inven- 
tion, which  no  doubt  would  be  used  in  America  today  if  it  had  not 
been  for  the  fact  that  it  is  diflicult  to  extract  these  primers  for  re- 
loading. They  have  two  small  flash  holes,  located  on  each  side  of 
the  primer  pocket,  instead  of  one  large  one  in  the  center.  These 
holes  are  much  too  small  to  permit  the  passage  of  a dc-capping  punch. 
The  Boxer  type  primer  with  its  self-contained  anvil  was  developed 
to  permit  easy  de-capping  for  handloading  purposes. 

Now  the  Europeans  all  use  the  Berdan  primer,  and  moreover,  the 
Western  Cartridge  Company,  who  made  8mm  Lcbcl  cartridges  for 
rhe  French  during  World  War  I,  made  them  with  the  Berdan  primer, 
and  liked  it.  A du  Pont  representative  for  a long  period  kept  more 


GtN  Corrosion  axi>  Aaimlmtiok  Develop mknts 


359 


or  Jess  pressure  on  Fraoklord  co  adopt  the  Berdan  primer,  in  the 
interest  of  better  ignition. 

All  this  resulted  in  the  development  of  a non-corrosive  primer  by 
Krankford  Arsenal,  uhicli  seemed  to  give  superb  results  in  primer 
coiTjponcncs  of  the  Berdan  type.  This  primer  composition  diifered 
from  the  Swiss  type  in  that  it  contained  no  fulminate  of  mercury. 
Fulminate  has  the  very  bad  habit  of  deteriorating  rapidly  in  moist 
humid  climates,  such  as  we  encounter  in  our  tropical  possessions, 
though  in  a climate  such  as  the  mountainous  one  nf  Swit7,erknd,  it 
is  ()iiite  satisfactory.  It  has  anotlwr  ilisadvanragc  from  our  v iewpoint, 
and  that  is  the  fact  that  cartridge  cases  fired  with  mercuric  primers 
become  brittle. 

Thus  wc  could  not  do  the  obvious  thing  and  copy  the  Swiss 
mixture,  but  we  did  succeed  in  getting  another  mixture  which  seemed 
even  better.  The  first  large  scale  trial  of  this  was  at  the  National 
Matches  of  J930,  where  Frankford  Arsenal  submitted  for  test  by  the 
Ammunition  Board  a lot  of  National  Match  Ammunition  loaded  with 
non-corrosive  primers  in  Berdan  primers. 


I 


Tins  lot  of  ammunition  won  the  test  with  one  of  the  best  accuracy 
records  ever  achieved,  and  was  duly  issued  for  use  in  the  National 
Aiatches.  Shortly  after  the  matches  started,  there  was  a spell  of 
abnormally  hot  weather  at  Camp  Perry,  and  it  was  found  the  ammu- 
nition was  giving  evidences  of  high  pressures.  The  Ordnance  Depart- 
ment thereupon  withdrew  this  lot  and  substituted  another  which  had 
the  regular  primer,  and  announced  that  experiments  with  Berdan 
primers  would  end  forthwith. 

I greatly  regret  that  1 was  absent  in  Europe  at  thai  time  with  our 
International  Kiflc  1*eam,  and  therefore  did  nut  sec  at  first  hand 
just  whar  happened.  Ii  would  seem  chat  with  every  other  nation 
in  the  world  having  used  Berdan  primers  in  every  kind  of  climate 
for  many  years,  the  trouble  might  have  been  due  to  some  other 
factor.  The  amimmicion  we  used  in  Europe  that  year  had  the  Berdan 
primer,  and  the  team  won  the  World  Championship  and  almost 
cvery'thing  else  in  sight.  This,  however,  was  low  velocity  atnnnmidon, 
especially  designed  for  best  accuray  at  300  meters. 

The  Berdan  Primer  fiasco  spelled  the  end  of  the  non-corrosive 
primer  in  service  ammunition  for  many  years.  Development  pro- 
ceeded feverishly,  and  all  the  commercial  ammunition  was  changed 
over  to  the  non-corrosivc  type,  but  the  rigid  Government  specifica- 
tions as  to  storage,  hang  fires,  etc.,  could  not  be  met  by  these  mixtures. 
Frankford  Arsenal  developed  some  promising  compositions,  bur  none 
gave  satisfactory  results  in  the  hangfirc  test,  which  was  imporiant  in 
those  days  nf  synchronized  airemfe  guns. 

This  was  the  siaiation  when  niobili7.arion  occurred  in  1940.  Im- 
mense orders  for  .30  Cal.  .Mi  ammunition  were  placed  with  the  various 
cartridge  companies,  and  there  was  quite  a bit  of  talk  about  non- 


Hatchfr’s  Notebook 


360 

corrosive  primers  by  some  of  the  companies,  who  thought  they  were 
prepared  to  make  them;  but  when  the  time  came  to  sign  on  the 
dotted  line,  none  of  them  were  willing  except  the  Canadian  firm  of 
Domini un  Industries,  who  in  1945  made  100,000,000  rounds  of 

cal.  .30  j\i  2 ammunirion  having  a non-corrosive  priiner. 

Ac  the  present  writing,  March,  1947,  wc  arc  changing  over  slowly 
to  a non-corrosive  printer  in  the  service  carrridee,  and  a porcion  of  this 
year’s  manufacture  will  have  this  type  of  primer.  The  change-over 
will  proceed  as  fast  as  ic  can  be  done  without  too  much  of  a dis- 
ruption of  production  until  all  ammunition  is  being  made  that  way, 
which  should  be  in  the  verv  near  future. 

4^ 


XV 

The  Pedersen  Device 


Most  of  our  Army’s  shoulder  amis,  be  they  hand  operated  or 
self  loaders,  have  been  well  known  co  the  shooting  public;  bui 
there  is  one  interesting  semi-automatic  fire  ann  chat  was  made  in 
great  quantities  for  the  Army  during  World  War  I that  has  received 
verj'  little  notice,  for  the  very  good  reason  that  at  the  time  of  its 
manufacture,  and  for  some  years  afterward,  the  War  Department  kept 
its  existence  a profound  secret. 

These  remarks  refer  to  the  “Automatic  Pistol,  Caliber  .30,  Model 
of  1918,“  otherwise  known  as  the  “Pedersen  Device, “ 65,000  of  which 
were  manufactured,  chough  up  to  the  end  of  the  war  its  very  existence 
was  know'n  to  only  a very  few  officers,  one  of  whom  was  the  present 
wTicer. 

In  spite  of  its  name  this  device  is  not  an  automatic  pistol  at  all,  bur 
is  best  desc^ribed  as  an  “automatic  bole"  for  the  Springfield  rifle, 
which  can  be  instanrly  inserted  in  place  of  the  regular  bolt.  It  is  con- 
structed to  receive  a magazine  holding  40  cartridges,  whicli  arc  of  .30 
caliber,  so  char  they  will  fit  the  barrel  of  the  rifle,  but  are  of  about 
the  same  size  and  power  as  the  .32  automatic  pistol  cartridge. 

When  the  device  is  fitted  to  the  Springfield,  the  rifle  is  thus  con- 
verted into  a 4o-shot  seiniauioiiuiiic,  and  becomes  a sort  of  submachine 
gun,  capable  of  delivering  a whirlwind  of  rapid  fire  instead  of  single 
shots. 

From  the  name  of  the  device  our  readers  will  deduce  the  fact  char 
it  is  the  invention  of  Mr.  J.  D.  Pedersen,  of  semiautomatic  rifle  fame. 
At  the  beginning  of  che  first  World  War  Mr.  Pedersen  was  already 
well  known  in  the  firearms  world  from  his  manv  successful  inventions, 
including  the  Remington  piitnp-accion  shotgun,  the  Remington  auto- 
matic pistol,  and  the  Remington  trombonc-accion  rifles  in  both  .2: 
caliber  and  high  power. 

In  the  summer  of  1917,  .Mr.  Pedersen  came  to  che  Wai*  Departmenc 
and  informed  die  chief  of  the  Small  Anus  Division  that  he  had  what 
lie  considered  a very  important  invention  which  he  wished  to  have 
cxiiinincd  secretly.  Because  of  .Mr.  Pedersen’s  prominence,  this  request 
was  immediately  granted,  and  only  one  or  two  high  officials  in  the 
War  Departmenc  saw  his  device  when  it  was  demonstrated  on  che 
Congress  Heights  Rifle  Range  in  the  District  of  Columbia. 

Mr.  Pedersen  began  his  demonstration  by  firing  the  Springfield 
rifle  which  he  brought  with  him.  After  firing  a few  shots  in  che 
ordinary  way  he  suddenly  jerked  the  bolt  out  of  the  rifle  and  dropped 

361 


ihc  ride  with  40  round  cna^ziiie  aciached  ready  lo  lire. 


The  p£i>£KS£N  Device 


3^3 

it  into  a pouch  which  he  had  with  him,  and  from  a long  scabbard 
which  was  on  his  belt  he  produced  a mysterious  looking  piece  of 
mechanism  which  he  quickly  slid  into  the  rifle  in  place  ot  the  bolt, 
locking  the  device  in  the  rifle  in  the  same  way  that  the  regular  bolt 
is  held  in  place;  that  is,  by  turning  down  the  cut-off.  Then  he  snapped 
into  place  a long  black  magazine  containing  40  small  pistol-size  car- 
tridges, whose  bullets  W'cre,  however,  of  the  right  diameter  to  fit 
the  barrel  of  the  rifle.  AH  this  was  done  in  an  instant,  and  in  another 
instant  Mr.  Pedersen  was  pulling  the  trigger  of  the  rifle  time  after  time 
as  fast  as  he  could  work  his  finger,  and  each  rime  he  pulled  the 
trigger  the  rifle  fired  a shot,  threw'  out  the  empty  cartridge,  and  re- 
loaded itself- 

It  was  really  a startling  demonstration.  In  firing  the  Springfield 
rifle  as  rapidly  as  it  can  be  done,  the  soldier  pulls  the  trigger,  turns 
up  the  bolt,  jerks  it  back  and  shoves  it  forward,  turns  it  down,  and 
then  is  ready  to  fire  one  more  shot;  but  with  this  new  device  of  Mr. 
Pedersen^,  all  that  was  necessary  was  to  keep  pulling  the  rrigger, 
and  the  rifle  did  the  rest.  When  the  magazine  of  40  rounds  was  empty, 
it  was  the  work  of  but  an  instant  to  snap  a new'  utaga/ine  into  place 
and  continue  firing. 

It  looked  as  if  Mr.  Pedersen  had  converted  the  Springfield  rific  into 
a one-man  machine  gun. 

A close  examination  of  the  device  showed  that  the  cartridge  he  fired 
was  only  about  onc-fifth  the  size  of  the  rifle  cartridge,  though  the 
bullet  was  the  same  diameter.  *l'hc  automatic  bolt  itself  was  found  to 
be  very  much  the  same  thing  as  a straight  ‘‘bio  whack’ ' type  auto  marie 
pistol  without  any  stock,  the  dimensions  of  what  would  otherwise 
be  a pistol  being  changed  suflicicntly  to  adapt  it  to  fit  in  the  rifle 
in  place  of  the  bolt.  The  barrel  of  the  [wstol  was  just  the  same  size, 
shape,  and  length  as  rhe  regular  Springfield  rifle  cartridge  {without 
the  bullet),  'fhis  little  barrel  is  rifled  with  fine  rifling  larger  in  di- 
ameter than  the  rifling  in  rhe  Springfield  barrel.  Thus  this  shore  barrel 
docs  nor  have  to  have  ihc  rifling  match  that  in  the  regular  barrel. 
The  sh()rr  barrel  starts  the  bullet  spinning,  hut  the  fine  rifling  does  not 
bke  in  very  deeply,  so  that  when  the  bullet  strikes  the  regular  barrel 
it  is  not  sized  down  too  small  for  the  regular  rifling  to  take  hold. 

The  device  was  adapted  m be  locked  in  place  in  the  receiver  by 
the  regular  magazine  cut-ofl*  uf  the  Springfield  rifle.  On  the  upper 
right-hand  part  of  the  device,  near  the  front  of  the  receiver  opening 
in  the  rifle,  was  a spring  catch  to  hold  the  long  magazine,  which  when 
placed  in  position  slanted  upward,  and  to  the  right  at  an  angle  of 
about  45  degrees. 

The  ejection  of  the  fired  cartridge  case  is  through  a port  on  the 
left-hand  side  of  the  device,  and  a corresponding  port  must  be  cut 
in  the  receiver  of  the  rifle,  as  can  be  seen  in  the  picture,  facing  p.  369. 


364 


Haicher^s  Noiebook 


The  Pedersea  Device.  ^h<mn  i^iih  tcs  ararnuiiiiion.  ilic  round  magazine,  and 
chc  meral  scabbard  u>ed  fur  carrying  the  dexice  on  the  soldier's  bell. 


The  PEDeRSEN  Device 


365 

It  will  thus  be  seen  that  a specially  modified  Springfield  rifle  is 
rc<^uired.  Not  only  does  the  rifle  have  ro  have  the  ejection  port  in 
the  receiver,  hut  Jt  must  have  two  grooves  ii\  the  magazine  cut-off, 
and  a little  kicker  in  the  sear. 

The  actual  release  of  the  firing  jnechanism  is  accomplished  by 
pushing  forward  an  a projection  on  the  bottom  of  the  device.  A 
little  pivoted  lever  in  the  scar  of  the  rifle  fits  in  the  notch  in  the 
bottom  of  the  device,  and  gives  the  necessary  forward  impulse  when 
the  trigger  of  the  rifle  is  pulled. 

The  Springfield  rifle  as  thus  modified  is  called  the  Mark  I.  These 
modifications  do  not  injure  the  rifle  in  anv  way  for  regular  shooting 
with  the  full-powcrcd  cartridge,  and  the  Klark  I rifle  is  just  as  good 
for  all  other  purposes  as  any  other  rifle.  Needless  to  say,  the  Govem- 
menr  manufactured  one  Mark  I rifle  for  each  Pedersen  device  which 
was  produced. 

Looking  at  the  picture  of  the  device,  it  will  be  seen  that  there  is 
a little  lump,  or  weight,  on  the  top.  Every  time  the  gun  is  fired  this 
lump,  w'hich  is  part  of  the  breechblock,  slides  10  the  rear  and  then 
jumps  forward  again,  something  like  a mouse  running  backward  and 
h)rw^ard  on  top  of  the  receiver.  It  is  the  inertia  of  this  w'eighc  which 
enables  a powerful  cartridge  to  be  used,  giving  the  very  high  velocity 
of  1,300  loot  seconds  as  against  800  or  900  foot  seconds  of  the  ordi- 
nary automatic  pistol  of  the  same  size. 

The  whole  device  in  its  metal  scabbard  weigh  2 pounds  and  2 
ounces,  and  the  loaded  magazine  filled  with  40  rounds  weighs  1 pound. 

Coming  now  to  ballistics,  the  new  cartridge  had  an  80-grain  bullet 
driven  by  grains  of  powder,  whereas  the  old  cartridge  had  a 
150-grain  bullet  driven  by  45  grains  of  powder.  In  the  old  high- 
powered  cartridge  the  bullet  leaves  the  muzzle  at  a velocity  of  :,7oo 
feet  per  second;  the  Pedersen  cartridge  leaves  the  muzzle  at  a velocity 
of  1,300  feet  per  second. 

As  die  eneigy  of  the  bullet  depends  upon  the  square  of  the  velocity 
as  well  as  upon  the  bullet  w'eight,  it  was  found  that  the  new  bullet 
had  a muzzle  energy  of  about  onc-tenth  that  of  the  service  cartridge. 
Tu  other  words,  while  the  bullet  of  the  service  cartridge  leaves  the 
muzzle  of  the  gun  with  an  energy  sufficient  to  lift  a ton  and  a quarter 
a distance  of  a foot,  the  new  bullet  had  only  sufficient  energy  to  lift 
one-cighth  of  a ton  a foot.  This  is,  however,  quite  sufficient  to  kill  a 
man  at  anv  range  up  to  500  vards,  or  sav  a little  over  one-quarter  of  a 
mile. 

Wliile  die  service  bullet  will  penetrate  60  inches  of  wood  a short 
distance  aw’av  from  the  gun,  the  new  bullet  will  penetrate  only  about 
8 inches,  or  the  same  that  the  service  rifle  w'ould  penetrate  one-half 
mile  away.  However,  a bullet*  which  will  penetrate  8 inches  or  ro 
inches  of  wood  will  easily  penetrate  a man,  and  it  was  apparent  at 
once  chat  this  system  which  enabled  a soldier  to  convert  his  rifle  at  a 


Tlie  PccUnen  Device.  ,>r  "U.  S.  .30  Calib«f  Pi'iu>l.  Model  of  191 R”  U ^ho«•n  in  the  cemer,  wiih  tomixineot  parts  shown  above  and  below. 


The  Pedersen  Device  367 

jDomcnfs  notice  into  a low-pmwered  inachine  gun  was  indeed  a most 
important  thing. 

The  War  Department  officials  who  saw  this  test  had  visions  of  what 
might  happen  in  case  of  an  attack  by  the  enemy  on  our  trench  system, 
should  our  men  be  armed  with  this  device.  As  the  enemy  came  charg- 
ing across  No  Man’s  Land,  each  of  our  soldiers  would  begin  firing 
with  this  miniature  machine  gun,  and  the  entire  zone  in  front  of  the 
trenches  would  be  covered  with  such  a whirlwind  of  lire  that  no 
attack  could  survive.  Also  it  looked  as  if  the  device  might  have  great 
possibilities  for  an  attack  starting  from  our  own  trenches.  For  one 
tiling,  there  is  no  noticeable  recoil  from  this  Pedersen  device,  and 
it  could  be  fired  from  the  hip  while  marching  or  running.  A line  of 
soldiers  advancing  across  No  Man’s  Land,  ^ing  this  device  at  the 
enemy  trenches  as  they  ran,  would  make  it  extremely  dangerous  for 
anyone  in  the  trenches  to  show  his  head  or  any  part  of  his  body, 
of  course,  fire  while  running  or  walking  would  not  be  so  accurate, 
but  the  tremendous  number  of  shots  would  more  than  make  up  for 
any  inaccuracies,  and  the  whole  enemy  trench  system  would  presum- 
ably be  smothered  with  a storm  of  l>ullcts. 

The  inventor  had  made  this  device  readily  interchangeable  with  the 
regular  rifle  bolt  so  that  the  bolt  could  be  put  back  into  the  rifle 
at  any  time,  thus  enabling  the  rifle  to  be  used  with  the  high-powered 
cartridge  when  this  seemed  desirable. 

It  was  proposed  that  the  soldier  should  ^0  into  battle  carrying  the 
usual  high-powered  cartridges,  and,  in  addition,  he  would  carry  this 
device  in  a scabbard  at  his  bek  as  well  as  a canvas  pouch  to  carry  the 
regular  rifle  bolt  when  the  device  was  being  used,  and  on  his  bde 
he  would  have  a canvas  case  holding  10  magazines  of  40  rounds  each 
for  the  device. 

This  development  appeared  so  important  that  an  officer,  who  was 
sworn  to  .secrecy,  was  p lacked  on  a ship  to  take  the  device  over  to 
France  and  explain  it  in  person  to  General  Pershing.  The  result  was  a 
code  cablegram  from  General  Pershing  calling  for  the  earliest  possible 
production  of  100,000  of  these  devices,  and  asking  that  the  whole 
project  he  kept  a profound  secret. 

Needless  to  .sav,  the  order  was  placed  at  once  and  the  secrecy 
which  already  surrounded  the  development  was  continued.  As  the 
name  ‘‘Pedersen  device”  seemed  to  be  sufficiently  mysterious  to  excite 
the  curiosity  of  the  people  w'ho  must  of  necessity  work  on  it  in  the 
various  factories,  a new  name  was  adopted  which  was  purposely 
made  not  at  all  descriptive  of  the  device.  This  name  was  “Auto- 
matic Pistol,  Caliber  .30,  Model  1918.” 

Of  course  the  Pedersen  device  was  in  no  sense  a pistol,  and  one 
of  the  amusing  incidents  connected  with  the  matter  is  the  fact  that 
some  writers,  who  in  some  way  heard  this  name,  criticized  the  War 
Department  severely  for  adopting  a smaller  caliber  pistol,  or  even 


n 


- -V 


■ 


^ 


i J 0 < t t'pn  Port 


U.  S.  Kitle,  CaJiber  .30,  M 19U3  Aiark  I.  with  hole  rcmi>v«d  lu  show  th<  special  ejeciion  pon  for  (he  Peder^n  Devitc  used  in 

ihh  >[ark  I RiAc, 


The  Pehersek  DeviCb; 


for  adopting  a new  pistol  at  all,  as  they  contended  that  our  .45 
automatic  pistol  was  sufficiently  good,  and  if  a new  pistol  were 
adopted  it  should  be  as  large  as  the  .45  instead  of  being  reduced  to 
.30  caliber. 

After  the  first  production  samples  of  this  gun  came  through  and 
it  began  to  be  definitely  determined  what  could  be  done  in  the  way 
of  manufacture,  another  officer  was  sent  to  France  for  further  com 
ference,  Asa  result  it  was  decided  that  500,000  Pedersen  devices  could 
be  ready  to  go  on  the  front  lines  in  the  sprii^  of  1919.  and  that  they 
would  be  utilized  as  a surprise  to  be  sprung  on  the  enemy  at  chat  time. 

It  is  an  interesting  speculation  to  think  W'hat  w^ould  have  occurred 
had  our  Army  started  to  cross  No  Man’s  Land  some  fine  morning 
with  half  a million  men,  each  armed  with  an  individual  machine  gun 
and  400  rounds  of  ammunition. 


Howe\'er,  the  old  weapons  wc  already  had  at  hand  proved  sufTi- 
ciemly  good  to  get  the  Germans  out  of  the  trenches  in  October, 
191 H,  and  the  war  ended  a month  later  with  65,000  of  the  Pedersen 
devices  completed.  The  remaining  orders  were  canceled. 

After  the  Armistice  of  November  it,  1918,  an  intensive  study  was 
made  of  the  possibilities  of  this  weapon  for  future  use.  One  of 
these  tests  was  made  at  Lc.Mans,  France,  and  was  attended  by  General 
Pershing  and  same  high  officials  of  his  staff. 

In  conducting  this  test,  a competitive  musketry  problem  was  con- 
ducted between  two  squads  of  officer  marksmen,  one  squad  being 
armed  with  Springfield  rifles,  and  the  other  with  rifles  and  the  Peder 
sen  Devices. 

These  officers  were  sworn  to  secrecy  before  the  test,  and  then 
were  given  enough  practice  to  familiarize  them  with  the  shooting  and 
handling  of  the  new  arm. 

A number  of  silhouette  targets  were  plac'ed  on  the  parapet  of 
the  target  pit  and  the  two  squads  each  had  a separate  group  of  sil 
houettes  to  fire  at.  The  squads  each  started  from  1000  varas,  Iving 
down  and  firing  until  a certain  number  of  hits  had  been  attained, 
when  the  pic  detail  would  pull  down  a red  flag  and  the  squad  could 
advance  to  the  next  station.  The  two  squads,  using  the  .30  caliber 
service  cartridges,  advanced  with  about  equal  speed  until  600  yards 
was  reached,  when  the  squad  wirh  the  Device  changed  bolts,  and 
started  using  the  automatic  bolt.  Iiiiiiiediatelv'  tliey  let  loose  such  a 
whirlwind  of  fire  that  the  flag  went  down  and  they  advanced.  This 
was  repeated  again  and  again,  until  they  had  gained  the  objective 
while  the  regular  squad  had  hardly  moved  from  600. 

All  officers  who  saw  this  demonstration  were  strongly  of  the 
opinion  that  this  wa.s  an  epoch  making  innovation  in  shoulder  weap 
ons. 


Mr.  Pedersen  and  I had  taken  to  France  the  Pedersen  Devices  and 
immunition  with  which  this  test  wa.s  conducted,  and  we  were  of 


370 


Hmcher’s  Norr:!ux>K 


course  present  on  rhe  ground,  .ic  the  time,  in  di<ngc  of  die  Ordnance 
arrangenicnrs. 

In  Septejiil)er,  1946,  after  I had  d cn  1 on sr rated  a Pedersen  Device 
at  Camp  Perry,  and  had  described  chi>  a member  «)f  the  Kxecu- 
tivc  Staff,  Col.  Gins  wold,  stepped  forward  and  said  that  he  had  been 
one  of  the  iJeiitenants  who  had  been  suorn  ro  secreev  and  assigned 
u)  the  target  pits.  The  pit  officers  lud  not  l»ecn  given  any  clue^^  as  to 
what  die  device  was  they  c)rganizcd  a (1-2  committee,  and  after 
the  firing,  they  went  to  ilic  firing  points  nrul  searched  for  an  empts 
cartridge  that  might  give  them  a due.  Alas,  the  fullest  of  precautions 
had  been  taken;  the  empties  had  been  carefuIK'  picked  up.  Never- 
theless, they  continued  to  search,  hoping  that  in  the  grassy  field,  at 
least  one  lone  carcridyre  midit  have  escaped  the  dean-up,  and  at 
fast  they  were  rewarded  hv  tindinc  one. 


The  author’s  son  Lieui.  Robert  D.  Hauher  sht'iotint;  the  Pedersen  Devkc  in 
March,  1947  with  4inmuniu\»ti  made  in  1918.  Tlii%  view  plainly  shows  the 
ejection  poet  in  the  left  side  of  the  receiver  of  the  Mark  I rifle.  The  empty 
carcndtfcs  were  thrown  just  to  the  left  of  (he  camera  lens. 


Ill  addition,  one  of  the  officers  had  carefully  studied  the  firing 
line  from  afar,  using  binoculars;  and  from  these  and  various  other 
fragments  of  infonnation  rhev  gradually  pieced  together  a theory 
of  the  device  which  was  just  about  right.  This  was  a nesv  viewpoint 
CO  me  on  something  that  1 saw  from  another  angle  in  those  days 
long  past. 


l llK  Pkdersln  Devkuc 


371 

At  the  close  of  World  War  I,  tliis  device  was  seen  in  the  light  of 
the  situation  that  had  just  been  passed  through;  the  years  of  intensive 
trench  warfare  on  an  almost  completely  stabilized  front.  Viewed  thus, 
it  looked  good;  but  when  this  perspective  had  faded  somewhat,  the 
picture  changed,  it  then  appeared  that  for  almost  any  other  kind  of 
cajiipaign  it  had  disadvantages  which  perhaps  rnirweighed  its  good 
points. 

Owing  to  the  light  weight  and  comparatively  low  power  of  the 
bullet  from  the  Pedersen  device,  it  is  accurate  against  individual 
targets  only  up  to  about  350  yards.  Beyond  chat  range,  it  is  difficult 
CO  hit  individual  targets  with  precision,  and  mass  tire  against  mass 
targets  must  be  depended  on.  Because  of  its  low  velocity,  it  has  a 
higTi  trajectory,  and  if  it  were  sighted  to  hit  a man  at  500  yards, 
the  bullet  would  pas.s  over  the  head  of  a man  at  }00  yards. 

Then,  again,  a more  serious  objection  is  that  at  the  present  time  the 
infantry  soldier  has  practically  cveiy^thing  he  can  possibly  carry 
loaded  on  him;  and  these  things— his  rifle,  bayonet,  ammunition,  and 
equipn^ent  pack— arc  all  things  which  cannot  be  discarded  01  reduced 
in  am'  way.  To  n»akc  him  carry  in  addition  a metal  scabbard  with 
the  i^edersen  device,  a canvas  p<nu:h  for  the  bolt  of  his  rifle,  and 
10  magazines  full  of  Pedersen  aniniunition,  would  be  practically  in)'' 
possible  in  anv  campaign  of  movement.  Greater  experience  has 
shown  that  if  the  soldiers  were  called  upon  to  advance  a certain 
distance  using  their  Springfield  rifles  with  the  regular  ammunition  at 
long  ranges,  and  then  at  some  point  in  (heir  advance  they  had  to 
change  to  the  Pedersen  device,  they  would  usually  reach  their  ob- 
jective without  the  regular  rifle  bolt,  as  this  would  be  lost-  dropped 

or  thrown  awav  in  their  excitement. 

# 

One  way  in  which  the  Pedersen  device  differs  from  the  Spring- 
field  rifle  is  in  its  comparative  silence.  When  the  Springfield  rifle  is 
fired  ic  makes  a verj'  loud  noise,  and  moreover  the  bullet  itself 
creates  an  air  w'avc  which  causes  a vicious  crack  whenever  the  bullet 
passes  a man  or  an  object.  Any  bullet  or  projectile  which  travels  at 
a speed  higher  than  the  velocity  of  sound  creates  tliis  air  wave  and 
makes  this  sharp,  menacing  noise  when  it  posses.  In  the  Pedersen 
device  the  powder  charge  is  small  in  relation  to  the  length  of  the 
barrel,  so  that  the  firing  of  the  gun  itself  makes  little  noise,  and  the 
bullet  itself  does  not  produce  the  air  wave  that  causes  the  bullet 
to  “bark”  when  ic  passes. 

In  one  of  our  peace-time  tests,  a number  of  soldiers  in  a pit  were 
operating  some  targets  which  were  being  shot  at  by  both  the  service 
rifle  and  the  Pedersen  device.  While  the  firing  was  going  on  with  the 
high-powered  cartridges,  the  soldiers  kept  down  as  low  as  possible, 
entirely  over  aw'ed  by  the  vicious  and  menacing  snap  of  the  high- 
powered  .50- ’06  bullets;  but  when  the  shift  was  made  to  the  Pedersen 
device,  holes  began  coming  into  the  target  faster  than  ever  but  without 


HAitiHZR’s  Notebook 


37i 

the  noise,  and  the  soldiers  all  got  up  as  high  as  possible  and  wanted  to 
look  over  the  edge  or  go  outside  of  the  trenches  to  see  what  was  going 
on.  J\s  a result  it  was  thought  by  some  of  the  observci-s  that  the  lack 
of  moral  effect  on  account  of  its  silence  was  a serious  disadvantage  of 
this  weapon.  Some  other  observers  of  this  incident  thought  that  this 
lack  uf  noise  pointed  to  an  advantage  for  the  Pedersen  device;  the 
enemy  would  be  bolder  about  leaving  their  cover,  and  \vould  become 
easier  targets.  However,  the  prevailing  opinion  was  that  the  menacing 
noise  of  the  Springfield  rifle  bullet  is  a decided  asset  owing  to  the 
moral  effect  it  has  in  instilling  fear  into  the  cnejny,  and  that  any 
weapon  which  lacks  this  noise  would  place  its  users  at  a disadvantage. 

The  restilt  of  this  gradual  change  of  opinion  was  tliat  a few  years 
after  die  end  of  the  first  World  War,  the  Army  decided  to  waste 
no  further  funds  keeping  these  devices  in  storage,  and  they  were  all 
destroyed,  and  the  Mark  I rifles  were  converted  back  to  regular 
Service  Rifles  by  the  removal  of  the  special  sear  and  the  cut-off 
with  grooves  in  ic  to  hold  the  device  in  place.  The  ejection  port  on 
the  rifle  remained,  together  with  the  wording  Mark  I,  and  the  few 
of  these  rifles  that  have  reached  the  hands  of  civilian  marksmen  have 
occasioned  quite  a bit  of  comment  from  the  usen,  most  of  whom 
never  heard  of  Pedersen’s  .jo  caliber  Pistol,  Model  of  1918. 


XVI 


Notes  on  Set  Triggers 

WHEN  an  individual  who  is  not  a shooter  picks  up  a rifle,  cocks 
it,  and  pulls  the  trigger,  the  trigger  pull  usually  seems  very  light 
and  easy  lo  him.  Bin  let  the  same  man  go  into  a marksmanship  contest, 
and  things  seem  ouite  different.  Every  time  he  gees  the  front  sight 
lined  up  on  the  buns -eye  and  tries  to  pull  the  trigger,  it  .seems  to  take 
a greatly  increased  amount  of  force  to  make  it  move,  In  other  \vords» 
marksmanship  makes  the  trigger  pull  seem  heavier. 

One  of  the  first  things  a mark^an  would  like  to  do,  therefore,  is 
*0  have  a lighter  and  easier  trigger  pull,  so  that  it  can  he  touched 
off  at  just  the  right  moment  wirhoiit  any  disturbance  to  the  rest  of 
the  gun. 

This  can  be  accomplished  to  a certain  extent  by  smooching  up  the 
sear  notch  and  the  sear,  and  by  making  the  engagement  of  the  sear 
with  its  notch  smaller  and  sinaQer,  so  that  there  will  not  be  so  mudt 
work  done  in  dksengaging  the  sear.  There  is,  however,  a limit  to  what 
can  be  done  along  this  line,  because  the  scar  usually  work.s  into  the 
notch  on  the  hammer  of  the  gun  and  the  hammer  is  actuated  by  a 
strong  spring.  The  notch  in  which  the  sear  is  engaged  is  close  to  the 
pivot  ot  the  hammer.  Therefore,  the  pressure  of  the  mainspring  is 
muiciplied  by  the  time  it  gets  to  the  scar  notch.  The  work,  therefore, 
of  pulling  the  trigger  i revolves  sliding  two  metal  surfaces  on  each  other 
while  these  surfaces  are  being  pressed  logcther  with  quite  a heavy 
force— namely,  that  of  the  mainspring,  multiplied  by  the  leverage. 

In  order  ro  make  the  easiest  possible  kind  of  trigger  pull,  ihe  set 
trigger  or  “hair  trigger,”  as  it  k sometimes  called,  was  devised.  These 
hair  trigger  guns  can  u.snally  be  recognized  by  having  two  triggers, 
something  like  the  double  trigger  of  a shotgun.  To  operate  tncni, 
ynu  pull  back  the  rear  trigger  until  it  snaps.  Then  w’hen  you  couch 
die  front  trigger  ever  so  lightly,  the  gun  will  go  off. 

Set  triggers  became  very  popular  in  this  country  over  one  hundred 
years  ago,  in  the  days  of  the  old  Kentucky  squirrel  rifles.  In  those 
days  the  standard  of  marksmanship  in  America  was  very  high,  and 
turkey  shoots  and  marksmanship  competitions  of  all  kinds  were 
popular. 

Many  of  the  old  Kentucky  rifles  that  have  been  handed  down  to 
the  present  day  are  fitted  with  set  triggers,  and  some  of  these  set  trig- 
gers are  jusr  xs  good  as  any  modem  set  trigger,  end,  in  fact,  would 
very  well  sen^e  as  a model  for  anyone  who  wished  to  build  a set 
trigger  today. 


373 


MaTCIIFR’s  NoiKftOOK 


374 

To  u riders tand  the  action  of  a sec  trigger,  look  at  Fig.  i,  wliicli  is 
a sketch  shoMnng  the  coniponenc  parrs,  also  the  assembled  view,  of 
the  set  trigger  of  an  old  Kentucky  rifle  in  possession  of  the  author. 
The  sear  proper  of  the  gun  engages  with  the  hammer,  and  is  pivoted 
on  the  lock  plate,  which  is  fitted  into  the  side  of  the  gun.  However, 


Diagram  of  Captain  Woody's  set  trigger. 


the  sear  has  an  arm  e.vtending  right  across  at  right  angles  to  the  lock. 
This  arm  rests  just  above  the  set  trigger.  Its  position  Is  anted  in  the 
sketch. 

Tlie  action  of  the  set  triggers  in  general  can  very  well  be  studied 
by  reference  to  the  lower  drawing  in  Fig.  t.  The  rear  trigger  is  in 
reality  a “knock-off’’  for  the  scar.  Tlic  heavy  spring  shown  to  the 
rear  of  the  trigger  tends  to  hold  the  rear  trigger  in  a forward  position 
with  its  forward  blade  kicked  up  into  the  air  and  rescinu  asainsr  the 
sear  arm. 

To  operate  cl»c  set  trigger,  the  gun  is  first  cocked.  I'hcn  the  rear 
trigger  is  pulled  back  as  far  as  pussUile,  until  it  is  locked  down  by 
the  point  on  the  front  trigger  which  engages  the  notch  nn  the  from 
part  of  the  rear  trigger.  The  engagement  is  very  slight  at  this  point. 
Moreover,  the  angle  is  such  that  it  is  ver\*  easy  to  slide  the  parts  out 
of  engagement.  The  slightest  touch  on  the  front  trigger  will  release 
this  contact  and  allow  the  heavy  spring  at  the  back  to  kick  the  arm 
of  the  rear  trigger  upward,  when  it  strikes  the  sear  arm  and  suddenly 
disengages  the  sear,  allowing  the  hammer  to  fall  at  the  same  instant. 

The  small  screw  between  rhe  two  triggers  limits  the  amount  by 
which  the  front  trigger  catches  onto  die  back  one,  and  thereby 
regulates  the  trigger  pull.  There  is  a backward  projecting  blade 
attached  to  the  front  trigger  which  operates  to  release  the  sear  when 
the  front  trigger  is  pulled  without  setting  it.  In  other  words,  unless 
the  rear  trigger  is  first  pulled  to  .sec  the  mechanism,  die  front  trigger 
acts  as  an  ordinary  trigger  when  pulled.  In  this  case  it  Avorks  with  a 
rather  hard  trigger  pull. 


Noi»;s  ON  Set  Triggers 


SeCTlOW  OF  FRAME 


TOP  VIEW  OF  FRAMe 


Vltw«  Thift/  ^FCIAf^ 
r^K,  Fn^CHT  TAI««CR 


TOP  View 


siofi  view  ^ 

THICK  ferRING-  FOR  PEAR  TRIGOER 


/fi^CAR  TRltOER 


FROWr  TRlG4ep 


SCAR  ARM 


PIG.  1 


IT 


( 


Figure  1.  Set  tri};i;er  Iron)  an  old  Keniucky  nllc  in  the  author’s  possession. 


Hatcher’s  Notebook 


376 

After  the  passing  of  the  old  Kentucky  squirrel  rifles  there  came  a 
gradual  lapse  in  marksmanship  and  competition  shooting,  during 
which  the  manufacture  of  sec  triggers  was  largely  discontinued. 
However,  in  the  latter  part  of  the  last  century  Schuetzen  shooting 
became  popular,  and  this  again  caused  a call  for  set  triggers. 

Ihcrc  were  two  wcil-known  makes  used  in  the  &huetzen  game, 
one  made  by  Stevens  and  the  other  by  Winchester.  Both  the  Win- 
chester and  Stevens  double  set  triggers  arc  of  exactly  the  same  type 
as  the  old  Kentucky  set  triggers  iflustnircd  in  Fig. 

One  of  the  finest  modern  sec  triggers  is  diat  on  the  Swi«  Martini 
rifles  our  International  Free  Rifle  Teams  used  in  1930.  It  differs  very 
materially  from  the  others  in  mechanical  construction,  for  instead 
of  having  just  two  levers  it  has  four.  Each  lever  reduces  the  yressui*e 
on  the  operating  edges  of  the  trigger  still  further,  until  with  four 
levers  the  pressure  at  the  point  where  the  front  trigger  engages  the 
ocher  mechanism  is  so  light  that  a trigger  of  this  kind  can  be  made 
very  sensitive  indeed.  In  other  words  the  more  levers  a gunsmith  puts 
into  his  set  trigger  rhe  easier  the  trigger  pull  is.  As  the  orher  triggers 
described  arc  all  rwo-tever  triggers  and  this  Martini  trigger  is  a lOiif' 
lever  one,  it  will  be  seen  that  the  seiisirivencss  is  multiplied  many 
times* 

Fig.  i shows  the  construction  these  foiir-lcver  triggers.  I'lio 
can  be  made  so  sensitive  that  a breach  of  wind  on  the  from  trigger 
will  cause  them  to  go  off,  chough  of  course  it  is  not  necessary  to  use 
it  as  sensitive  as  this  at  all  times. 

When  the  United  States  first  went  into  the  Intcriiatinnal  Match 
shooting  just  after  World  W’ar  1 the  ream  used  set  triggers  which 
were  bought  in  Germany  by  members  of  the  iot«  Armv  of  Occupfl' 
non.  These  scr  triggers,  made  to  fit  the  Springfield  rifle,  are  of  the 
iwo-levcr  type,  identical  in  consrniction  with  that  of  the  Old  Ken 
uickv  rifle  above  described. 

In  this  German  trigger  there  is  a special  cam  lever  placed  in  the  scar 
of  the  Springfield  rifle,  and  when  rhe  front  trigger  is  touched  the 
rear  trigger  flie.s  forward  and  the  upper  arm  of  the  rear  trigger 
strikes  upward  on  this  sear  cam,  and  the  action  causes  rhe  sear  to 
be  cammed  down  out  of  engagement  with  the  striker.  There  is  a 
certain  loss  of  time  to  this  reverse  motion  on  the  scar  lever  and  sear, 
which  is  one  of  the  disadvantages  of  this  type  of  trigger.  Another 
disadvantage  is  the  face  that  it  was  only  the  double-lever  type,  and 
therefore  not  as  sensitive  as  might  have  been  desirable. 

It  is  this  set  trigger  which  our  International  Rifle  Team  used  in 
the  victories  of  1921  and  1922.  The  hope  of  improving  the  set  trigger 
used  at  that  time  led  to  rhe  design  of  several  set  triggers,  the  most  suc- 
cessful of  which  u'as  made  bv  Sergeant  Rinkounis,  of  the  Marine 
Corps,  whose  set  trigger  worked  in  the  opposite  direction  and  jerked 
the  sear  down  instead  of  striking  an  upward  blow  first.  Oscillographs 


Notes  on  Set  Triggers 


111 

showed  chat  the  Rizikoiinis  trigger  was  faster  than  the  German  type, 
and  ic  was  used  on  the  victorious  American  Rifle  Team  of  1924  by 
some  members,  while  other  members  used  the  German  trigger. 

The  Rinkounis  trigger  was  used  in  1925,  but  did  not  give  satis- 
faction because  it  was  a handmade  job,  and  there  was  a certain 
amount  of  trouble  with  sloppy  pieces,  etc.;  and  besides,  being  only  a 
two-lever  trigger,  it  was  not  capable  of  as  much  sensitiveness  as  was 


Figure  2.  Four-lever  set  tfi^er  from  a mndern  Martini-type  European  match  rifle. 

thought  desirable.  Accordingly,  the  late  Colonel  Woody,  of  Frank- 
ford  Arsenal,  made  up  a set  trigger  for  the  use  of  the  1927  Inter- 
national Rifle  Team.  The  Woody  set  trigger  is  a four-lever  trigger 
and  is  an  improvement  on  the  best  Swiss  triggers.  In  the  Woody 
trigger  one  of  the  delicate  springs  used  in  the  Swiss  triggers  is 
eliminated  and  the  leverages  are  improved.  This  trigger  gives  a re- 
duction of  pressure  on  the  contact  points  of  40  to  i.  For  equal 
sensitivity  with  a two-lever  trigger,  the  rear  trigger  would  have  to 
have  a forward-projecting  arm  about  6 inches  long,  whereas  in  actual 
practice  the  forward  arm  of  a two-levcr  trigger  is  about  three- 
qtiarrcn  of  an  inch  long. 


378  Hatcher’s  Notebook 

The  view  of  the  Woodv  set  iriggei*  assembled  in  the  Springfield 
rifle  is  shown  in  Fig.  3. 

Haeitnncrli  s Set  Trigger 

An  excellent  set  trigger  for  the  Martini  rifle  is  the  5 -lever  set  trigger 
made  by  Haemnicrli  & Co.,  of  Switzerland.  This  Is  the  trigger  clut  was 
used  by  the  Swiss  team  in  the  1928  Incemacional  Match  in  Holland. 

The  mechanism  of  this  trigger  consists  of  a train  of  five  levers 
actuated  by  one  heavy  spring  and  four  light  springs.  The  arrangement 
is  contpact  and  ingenious  and  permits  of  very  close  adjustment.  A 
set  screw  regulates  the  pressure  required,  which  can  be  set  down  to 
the  lightest  coucl»  or  a heavy  breath. 


Figure  5.  WawK  rrigper  assemMcd  In  fiftc  action. 


The  trigger  is  e.vtreinciv  smooch  in  action.  1*1 1 ere  is  no  creep, 
looseness  or  side  play.  The  five  levers  permit  a very  light  pressure 
between  engaging  surfaces  for  the  last  stages  by  which  an  improve- 
ment in  smoothness  is  gained  over  triggers  of  four  levers  or  less  with 
no  appreciable  loss  in  the  time  clement. 

This  trigger  appears  to  be  capable  of  bcinc  built  into  a trigger 
guard  for  the  Springfield  action,  as  the  kick-off  feature  is  similar  to 
that  of  the  various  types  of  triggers  in  our  heavy  Springfield  Match 
rifles. 


Notes  on  Srt  I'riooers 


379 

Using  a set  trigger  is  quite  different  from  using  an  ordinary 
trigger  and  requires  a completely  different  method  of  handling  the 
gun,  and  really  requires  long  and  persistent  training  to  he  mastered. 
In  the  first  place,  the  set  trigger  is  dangei-oiis  to  use  unless  very 
special  precautions  are  taken,  because  with  the  best  of  sec  triggers 
and  the  best  of  marksmen  there  are  bound  to  he  accidental  dis- 
charges. For  this  reason  special  rules  are  made  for  matches  in  which 
set  triggers  are  used.  A set  trigger  must  be  “set’'  after  the  gun  is 
loaded,  because  the  action  of  closing  or  opening  the  bolt  will  almost 
certainly  set  off  the  trigger  just  from  the  jar. 

Therefore,  the  gun  is  loaded  with  the  barrel  resting  upon  a support 
and  pointing  at  the  ground.  While  the  muzzle  is  still  resting  upon  this 
support  the  rear  .set  trigger  is  pulled  hack  so  that  the  triggers  are  sec. 
Sometimes  accidents  occur  at  this  point  and  aeddentaf  discharges 
may  be  expected.  The  rules  do  not  count  sucli  an  accidental  dis- 
charge against  a marksman  provided  the  barrel  of  the  gun  is  resting 
upon  the  support  when  the  discharge  occurs*,  but  if  the  barrel  of 
the  gun  has  left  the  support  and  an  accidental  discharge  occurs,  the 
marksman  gets  zero,  or  whatever  his  bullet  makes  on  the  target. 

Using  a set  trigger  for  the  first  lime  usually  makes  a jnan  who  has 
been  using  only  an  ordinary  trigger  very  nervous.  It  is  like  fooling 
with  dynamite.  The  slightest  couch  makes  it  go  off.  The  man  using  a 
sec  trigger  for  the  first  time  would  make  a much  worse  score  chan 
he  would  with  an  ordinary  trigger.  In  fact,  1 am  nor  so  sure  that 
some  of  our  International  .Match  shots  would  not  have  done  better 
with  ordinary  triggers  throughout  the  entire  match.  By  this  I mean 
the  old-timers  of  the  Marine  and  other  Service  ‘reams,  who  have  had 
years  of  experience  with  the  regular  trigger. 

In  using  the  ser  trigger  rhe  methods  of  different  operators  vary 
considerably.  Usually  the  forefinger  is  not  placed  in  front  of  the 
trigger  but  <mly  the  side.  Great  care  must  be  taken  in  placing 
the  finger  against  the  trigger  not  to  make  the  sec  trigger  go  off  from 
the  mere  fact  of  touching  it.  One  man  that  I know  who  is  very  good 
on  using  a set  triirger  alw'ays  approaches  the  front*  trigger  with  a 
forward  motion  of  his  finger,  so  that  when  the  finger  finally  touches 
the  trigger  the  tendency  is  that  it  slierhtlv  presses  the  front  trigger 
forward.  Then  there  is  no  danger  of  the  guns  going  off  when  the 
trigger  is  being  touched. 

The  next  thing  chat  happens  is  that  the  user  aims  at  the  target, 
and  when  he  gets  the  sights  into  the  proper  position  he  merely  relaxes 
his  forefinger  slightly,  and  the  gun  seems  to  go  off  of  its  own  accord. 

When  a set  trigger  gun  ha.s  been  tx>ckcd  and  the  trigger  is  set  It 
is  a rather  ticklish  thing  to  mODkey  with,  but  it  is  easy  to  unload 
without  danger.  This  is  dune  by  first  putting  the  middle  finger  on 
the  rear  trigger  and  pulHr^  this  back  as  far  as  possible,  then  placing 
the  forefinger  on  the  front  trigger  and  pressing  it  to  the  rear.  Then 


Hatcher’s  Notebook 


380 

let  the  rear  trigger  go  forward  slowly.  The  triggers  are  then  released. 
This  should,  of  course,  he  done  with  the  ma^^le  of  the  giui  pointing 
in  a safe  direction. 

Though  all  set  triggers  are  somewhat  ticklish  to  use,  ciiere  is 
absolutely  no  doubt  that  with  practice  in  their  use  they  can  help 
ro  make  wonderfully  high  scores,  especially  in  the  standing  and 
kneeling  positions. 


XVII 


Random  Notes  on  Various  Subjects 

1.  Th«  Men  Behind  the  Guns 

Ir  has  been  a most  jnteresring  experience  through  the  years  to  have 
been  more  or  less  closely  associated  with  many  of  the  men  who 
made  the  guns  we  have  discussed. 

To  list  some  of  them  in  alphabetical  order,  there  arc  Soren  Hansen 
Bang,  of  the  Danish  Recoil  RiHc  Syndicate,  and  Laurence  \^  Benet, 
of  rlic  Hotchkiss  Clonipanv,  who  designed  the  Benet Mercier.  Still 


John  M.  Drowning,  famous  inventor  of  rifles,  shotguns.  pt$toI$  and  machine 
gun$.  He  was  born  io  Ogden,  Utah,  in  1855,  and  died  in  1926. 


in  the  B’s  we  have  General  Berthier,  who  lived  in  Springfield  for 
some  months  during  i9i7»  when  1 wax  in  charge  of  the  tests  of  his 
gun  that  was  l>eing  modified  and  re-submitted  from  rime  to  time. 

381 


IKichrk's  Non-KOf^K 


John  C.  CiArrtml.  dt'iyncr  id  the  I'.  S.  Riflf.  C4lil)et  .V),  M I.  He  pronouiu e> 
lus  n.imt  (irramh  >viih  ihe  0 hifd  4s  in  gOy  and  die  stress  on  the  ftr«  syllable, 
lo  rhyme*  >viih  parent. 

Vill  A.  Browning  who  itiherkcd  inucli  of  ihe  genius  of  his  father 
Jo!m  M.,  was  an  Ordnance  Officer  with  whotu  I \vas  closely  associated 
in  World  War  I.  He  \vas  the  first  man  to  fire  a Browning  Automatic 
Rifle  in  action  in  France  in  iqj8.  Ac  this  writing,  1947,  president 
of  the  firm  of  J.  M.  & M.  S.  Browning  whicl^  was  founded  by  his 
father  and  uncle  in  Ogden.  Utah. 

John  C Garand,  our  top-notch  gun  designer,  has  personal  qualities 
that  endear  him  to  all  his  acquaintances.  Both  my  brother,  Col. 
James  L.  Hatcher,  himself  a gun  designer  of  great  ability,  and  I have 
long  counted  Mr.  Garand  as  n close  and  valued  friend. 

Gerlich,  originator  of  the  “Ilalgcr’  high  velocity  system,  Karl 


John  M.  Browning  arul  his  brother  A bit  t he  w'  S.  Browning  and  his 
half-brother  J.  Edmund  Browning  were  valued  friends.  “Mate”  and 
‘‘Ed’'  were  rnightv  clever  cun  designei*s  in  their  own  rights;  a semi- 
autojnatic  rifle  designed  bv  Ed  Browning  and  submitted  by  Win- 
chester was  a strong  contender  in  (»uvcrnmciit  tests  as  recently  as 
the  beginning  of  World  War  Tl. 


Nou  s iJ.N  V'aKKK^S  Si  I’.JK  I''  383 

rieiricimnn^  ujvcntnr  of  the  Piiralielliim  Machine  (lun  anil  the  IJcinc- 
Tiiaim  Semi-auLomaiic  Rillc,  and  Grant  Hammond,  of  pistol  fame 
were  each  with  us  only  a few  days  during  tests  wc  made  of  cheir 
inventions,  but  even  to  nicer  and  talk  with  them  briefly  was  quite 
interesting. 


J.  1).  Poder94^,  famous  armc  dedgner.  PhiKo  hy  dig 

Auihor.  15  April  1946. 


Cape.  ‘‘MeV’  Johnson,  brilliant  creator  of  the  Johnsmi  autmiiaiic 
rifle  and  the  Johnson  l.ight  Machine  Giin  is  another  rop-notch  gun 
designer  that  it  is  a privilege  to  know. 

The  late  Col.  1.  N.  Lewis,  of  Lewis  Gun  fame  was  known  chiefly 
for  his  Depression  Position  Finder  \\hen  1 served  with  him  at  an 
Artillery  post  many  years  ago. 

General  Liu  of  China  brouffhe  his  Semi-Automatic  to  Springfield 
for  me  CO  test  in  the  early  part  of  1918.  As  wc  both  spoke  French 
pretty  fluently  at  that  time  I was  able  to  learn  quite  a lot  from  him. 
He  was  a brilliant  mechanical  engineer  and  gun  expert. 

J.  D,  Pedersen  is  a designer  of  whom  Mr.  Browning  thought  very 
liighly.  He  once  told  me  that  Pedersen  was  the  greatest  gun  designer 
in  the  world,  My  association  with  him  dates  from  1918,  when  work 


HAICHtHJ*  NuiKbOOK 


on  hii  Pcdei'Aen  Dcvicw  brought  us  u>gccljci.  VV'c  uiok  trip  to 

Europe  together  to  demonstrate  his  device  and  to  arrange  a field 
trial  of  it  for  General  Pershing.  Jiisc  before  this  was  written  he 
spent  an  evening  at  my  house  and  we  had  a very  pleasant  time  dis- 
secting and  discussing  a German  Gew.  45. 


Colonel  'l\iwnscn<l  Whelcn,  U.  5.  Atmy,  KciircJ.  He  cujoys  a world-wide 
repLiUhon  u.s  a big  game  burner,  au(bor  and  Krearms  authority. 

Eugene  Reising  has  been  working  on  guns  a long  limc;  I first 
knew  him  when  he  was  working  on  his  auroimtic  .22  caliber  larger 
pistol.  He  is  responsible  for  the  subiiiachinegim  made  bv  Harringum 
^ Richardson  during  World  War  II. 

Maj.  Searlcs,  who  invented  the  Savage  Auromatic  Pistol  was  an 
Ordnance  Officer  during  World  War  I,  and  1 saw  iuni  frw^uently 
at  that  time,  as  I did  A.  W.  Swebilius,  the  talented  producer  of  the 
Marlin  Aircraft  Machine  gun.  I still  enjov  seeini?  him  occasionallv 
at  his  High  Standard  .Manufacturing  Co.  in  New  Haven,  where 
in  this  year  of  1947  he  is  still  doing  some  mighty  fine  gun  designing. 

General  John  T.  Thojiip^on  of  ‘‘'rominy  C^un”  fame  and  inventor 
of  the  Thompson  Autorifle  was  in  charge  of  rhe  Small  Arms  Division, 
Ordnance  D^arcment  when  I first  knew  him. 


Kai^dom  Notes  on  Various  Subjects 

Mr.  David  M.  Willianis,  of  Godwin,  North  Carolina,  inventor  of 
many  importanc  firearms  designs  and  mechanisms,  including  the 
short-stroke  piston  principle  as  used  in  the  U.  S.  Carbine,  Cal.  .30, 
M I,  and  the  floatin?  chamber  ased  in  the  U.  S.  .22  Caliber  Machine 
Gun,  the  Colt  Service  Ace  Pistol,  and  some  Rcunngton  Rifles. 


Captain  Melvin  M.  Johnwin^  designer  of  the  Johnson 
Semi-jiutomatic  Rifle  and  the  Johnson  Light  Machine 
Guo. 

There  are  no  doubt,  many  more  whom  1 have  forgotcon  to  include, 
even  as  I write  these  lines  I recall  Manning  of  the  Murphy-Manning 
gun,  White,  who  had  a very  promising  Semi-automatic  rifle;  Coi. 
Richard  M.  Cutts,  U.S.M.C.,  and  his  son  Captain  Cutis,  originators 
of  the  Cutes  Compensator;  and  last  but  not  least,  Hudson  Maxim, 
noted  inventor  of  smokeless  powders,  and  brother  of  Sir  Hiram 
Maxim. 

2.  National  Match  Ammimition 

Prior  to  World  War  1,  die  Govern  mem  regularly  obtained  the 
then  standard  .30  Caliber  M 1906  ammunition  from  Frankford  Arsenal 


i lATCIItR’s  NOI KUOOK 


yH6 

and  from  the  large  commerckl  cartridge  companies.  It  was  usual  co 
hold  a competition  each  year  to  determine  which  of  the  makers 
should  furnish  the  ammunition  to  be  used  in  the  National  Matches 
of  that  year. 

The  various  makers,  including  Frankford  Arsenal  would  each  sub- 
nut  their  best  sample  for  rest  by  the  Ammunition  Board.  The  winner 
would  get  the  contract  to  furnish  the  ammunition  for  the  matches. 
This  was  all  the  standard  .30  Cal.  iM  1906,  made  to  the  regular 
specifications  calling  for  a 150  grain  flat  base  cupro-nickel  jaclceted 
bullet  driven  by  a charge  of  approximately  50  grains  of  Pyro  D.  G. 
Powder  at  a muzzle  velocity  of  2700  feet  per  second,  and  with  an 
average  pressure  which  varied  with  the  powder  lor,  but  was  usually 
somewhat  under  5o,o<k>  pounds  per  sejuarc  inch. 

Ac  the  end  of  World  War  I,  the  Government  was  greatly  over- 
stocked with  ammunition,  and  stopped  buying  it  commercially.  Kx- 
pcrlmenrs  were  started  to  develop  an  improved  type  of  ammunition, 
and  for  several  years  the  National  Matches  furnished  a proving 
ground  for  the  exuerii neural  types. 

By  1925  the  Mi  amniimirion  had  been  sunda rdized,  with  a 172 
grain  boar  tailed  bullet  having  a 9 degree  laper  at  the  base,  and 
jacketed  with  gilding  mccal.  At  first  rim  bad  a muzzle  velocity  of 
about  2700  f.s.,  which  was  later  reduced  to  2640. 

In  1926  there  were  no  National  .Marches.  In  1927  the  1925  National 
Match  ammunition  remaining  on  hand  was  used.  In  192 K ordinary 
Mi  ammunition  was  taken  from  stock  for  the  matches.  This  was  so 
It  n satis  factor)'  chat  the  production  of  a special  lot  of  National  Match 
iunmuiiitinn  was  resumed  in  1929.  In  1930,  National  Match  aimnunU 
cion  was  made  to  try  out  the  possibilities  of  the  Berdan  primer.  This 
gave  unexpectedly  fiigh  and  erratic  pressures  during  a spell  of  un- 
usually hot  weather  at  the  marches,  so  was  abandoned. 

National  Matches  since  that  time  have  been  fired  with  service 
ammunition,  selected  from  lots  which  show  better  than  average 
accuracy  in  final  inspection. 

The  Js’acional  matches  with  the  service  rifle  were  suspended  at  the 
beginning  of  World  War  II  and  at  this  writing,  March,  1947,  have 
not  been  resumed. 

The  following  recapitulation  gives  the  characteristlc.s  of  the  Na- 
tional Match  Ammunition  for  the  various  years: 


CAUSER  .30  SATiONAL  MATCH  AMMUNITION 

(FraAkford  Aj^oal) 


Year 

Bullet 

Powder 

Type 

Chg. 

Gr. 

Insi.  Vd. 
at  78  Ft. 

Mean 

Mean 

RadfiiK 

Pressure 

600  Yds. 

1000  Yds. 

19x9 

150  Gr. 

F.  B.  CuNi 

Pyro 

#1406 

46.5 

2^40 

47i^ 

5.19" 

9/5j" 

1920 

170  Gr, 

F.  B.  CuNl 

Pyro 

#i4od 

' 4^«5 

2550 

47.5«> 

4*74" 

10.24" 

1921 

170  Gr. 

F.  B.  CuNL 
Timied 

DuPont 

#1076 

48-2 

2d00 

48.7*5 

3.00" 

8,5," 

1922 

T70  Gr,  6* 
B.r.  G.M. 

Hi  Vd 
#!d-888 

454 

2^2 

ATk  AATK 

m8' 

7.22" 

i9;j 

170  Gr.  6* 

nr.  OM. 

Hi  Vet 

45-5 

5^53 

47-ow 

2,85" 

6,662" 

1924 

170  Gr.  9* 
B.T.  G.M. 

Hi  Vd 
#i4B6 

4d.| 

2<44 

47i«»o  1 

2.J6" 

5.685" 

1925 

T70  Gr.  9* 
B.T.  G.M, 

1MR-]  147 
#1489 

53* 

27164 

1 

49.640 

2.J0’' 

5.710" 

192^ 

X70  Cr.  9* 
B.T.  G.M. 

IMR-XI47 

#1491 

5*-9 

2700 

$0/»o 

1 

1 No  Test  Held 

No  Test  Held 

1927 

172  Gr.  9* 
B.T.  G.M. 

fMR>iJ47 

#1489 

53-* 

27164 

49*^ 

•2.30" 

•5.710" 

1928 

172  Gr.  9* 
B.T.  G.M. 

IMK-nSc 

kim 

40A 

4*4?«>5 

3.04" 

8.CXJ" 

1929 

173  Gr.  9* 
B.T  G.M. 

IMR-iiSd 

#1619 

49J 

2692 

5*4<w> 

3.06'' 

7.05" 

19J0 

J73  Gr.  9* 
B.T.  G.M. 

IMR'ii86 
#i6zo 
THIS  AMN 

iu>jrnoN  CO? 

2686 

4TAIN1NG  BEP 

5 1.795 

IDAN  PRIMER  NOT  USED 

5.16" 

19JO 

173  Gr.  9* 
B.T.  GJM. 

lMR-1186 

#1^35 

49-5 

THIS  AMMUN 

1 1 

2645  1 47^52 

mON  USED  IN  MATCHES 

*•77"  1 

7.18" 

*2925  Over-rua  used  in  1927  # Lor  Number 


Ranw)\j  NirrFs  on  Varioi’s  Si  ructs 


3^8  Hatchkks  NoitBooK 

i.  Caliber  JO  ImeroatsoDal  Macch  Acumuiiiiion 

Up  until  1930,  the  United  States  used  to  send  a team  each  year  to 
compete  in  the  Free  Rifle  jMacches  of  the  Internacional  Shooting 
Union.  As  this  type  of  shooting,  with  heavy  barrelled  Schuetzen  type 
rifles  was  not  popular  in  the  United  States,  wc  always  had  difficulty 
in  getting  up  a team  that  would  be  truly  representative  of  a cross 
section  of  the  nafioii’s  shooters,  so  participation  in  these  matches 
was  discontinued  after  the  matches  in  Antwerp  in  *930  when  the 
team  of  which  the  author  \tas  manager  vv4in  the  World  Championship 
and  numerous  individual  titles. 


mAMKfOM  tMtniA.  AMMUNIOM 


urgecs  were  ^h»>r  during  the  dev«lopm«iii  of  liHernatioua]  and  Palma 
Match  amirmnition  white  ihe  auihor^  lh«n  4 major,  vs  as  in  charge  of  ammnnttion 
macufaicure  ai  Frankford  Arwnal.  The  icmcr  ring  of  (he  left  hand  target  U 
3.  IS/ Hi  inch  in  diameicr,  and  the  group  fired  at  328  >ard$  was  1.55  inches  in 
diameter,  or  4/10  of  a minute  wide.  The  same  len  shots  caught  on  another 
screen  at  600  yards  are  shown  on  a 20  inch  bullseyc.  The  group  at  600  yards 
was  3.1^  inches  in  diameter,  subtending  just  over  S'ltJ  of  4 minute. 


From  the  close  of  Workl  War  I until  ly^o,  it  was  the  custom  to 
have  a competitive  test  each  year  to  select  the  ammunition  to  be 
used  in  these  matches. 

Particulars  of  ammunition  with  results  of  the  tests  are  given  below: 


The  author  at  Disley,  £a^UuU.  in  Captain  of  the  L'niced  Sutes  Rifle  Team, 


CO 

o 


S.llMHV  \ \t)  bd.UtJ^  lUKlSV>j 


CAUBER  .io  tSTERSATlONAL  MATCH  AMMUSiTION 


Year 

Bullet 

Pow'dcr 

Type 

Chg. 

Gr. 

Inst.  Vel. 
at  78  Ft. 

1920 

180  Gr. 

F.  R.  CuNi. 

I.MR.I5JI 

5»*5 

2670 

1921 

1922 

44  * * * 

1923 

180  Gr 
F.  B.  CuNI. 

2870 

J924 

i8o  Gr. 

F.  B.  CuNI. 

HIVel 

4^3 

2dro 

J925 

lyi  Gr.  9* 
B.T.  G.M, 

HiVel  #2 
Lot  14^1^ 
Bl.  #9 

}7^ 

2199 

192^ 

1 

! 

1 

1 

1927 

172  Gr.  9* 
DT.  G.M. 

HiVd  #2 
Lor  1488 
-S 

3^4 

1 

2203** 

1928 

171  Gr.  9* 
BT.  G.M. 

1MR-II47 
Lot  1492 

31.1 

17.5,.*- 

1929 

C73  Gr.  9* 
B.T.  G.M. 

IMR 
Lot  idi? 

52.0 

2712 

1 

1930 

173  Gr.  9" 
B.T.  G.M. 

HiVel  #2 
Lot  H-93 
-808 

33-5 

2219 

1 

Mean 

Pressure 

Mean  Radius 
300  .Meters 
(Computed) 

Fig.  of 
Merit 
300  Met. 

Mfgr. 

It 

Remarks 

46^ 

‘•5?" 

Rem. 

No 

Test 

1 

No 

Test 

46.W 

1.09" 

iAo6" 

Rem. 

46.200 

1.02" 

1 

J..79'* 

Rem. 

«9i543 

.844" 

:.xr 

FA. 

No  Match  No  Test 

•ysr 

M3" 

FA. 

42,650 

l.io'' 

J.85" 

FA. 

4t.*70 

1.14“ 

J.96" 

FA. 

J748> 

241'' 

F.A. 

Figure  of  merit  for  1924  was  at  300  yards  instead  of  meters. 
Velocity  was  taken  in  30  inch  barrel  in  T928. 


Veloekv  was  taken  in  2S  inch  barrel  m 1927 


J Li  >1^  inu V J I 


Random  Navtib  on  VARiues  Subjects  391 

4.  Palma  Mateh  Animuniiioit 

For  the  Jong  range  International  Palma  Match,  the  utmost  accuracy 
at  tong  range  is  required  in  the  ammunition.  Immediately  after  World 
War  1 it  became  the  custom  to  hold  a competitive  accuracy  rest  of 
ammunitioa  to  determine  the  ammunition  to  be  used  in  this  match. 

The  particulars  of  the  anuiiunition  selected  each  year,  together 
with  the  result  of  the  official  test,  is  given  below.  It  will  be  noted 
chat  in  several  years  there  were  no  rests,  and  chat  in  1^30,  the  am- 
munition which  won  the  competition  was  afterward  withdrawn  from 
use  because  of  high  pressures  which  were  blamed  on  the  Berdan 
primers  used  in  this  lot. 

Another  lot  without  the  Berdan  primers  was  hastily  substituted 
without  any  official  test. 


CALIBER  .30  FALMA  MATCH  AMMUHITIOH 


Year 

BuUet 

Powder 

Type 

1 

Oig. 

Gr. 

1 

Tost.  Vcl. 
■ at  78  Ft. 

Mean 

Pres. 

Mean 
Radius 
1000  Yds. 

Mfgr. 

& 

Remarks 

1920 

1 

1 

No  Mfg. 

1921 

170  Gr. 
F3.  CaNi. 

duPortt  Ex. 
No.  io;d 

■»8-> 

2^00 

4 

6.04"*’' 

5.^ 

• .A." 

Remington 

1922 

180  Gr. 
F.B.  I.ubaloy 

HiVel 
Lot  #1 

46 

2^2^ 

49»865 

1 

Western 

*9*3 

i 

• • • i * « * ♦ 

No  Mfg. 

*9*4 

200  Gr. 
F3.  CuNi. 

HiVel 

445 

1 

*477 

4«,i8o 

5497 

Remington 

19*5 

172  Gr.  9* 
B.T.  G,M 

IMK-H47 

545 

»77« 

5l.3"5 

1 

1 

443" 

Frank  FA. 

1916 

No  j\lfg. 

1927 

No  Mfg. 

1929 

172  Gf.  9* 
B.T.  G..M. 

LMR-M47 
Lot  (492 

51.1 

2715.1 

42,650 

(Computed) 

F.A..  Same  as 
[nternational 

1929 

*73  Gf.  9* 
B.T.  G.M. 

IMR-i(8« 
I.cit  1619 

49.8 

2700 

19.<«5 

5.«7- 

F.A. 

1930 

*73  Gr.  9* 
B.T.  G.M. 

Lot  (620 

51.2 

2712.2 

54i335 

5.10- 

F.A.  (Not 
Used;  Berdan) 

1930 

*73  Gr  9* 
B.T.  G.M. 

IMR-1147 
Lot  i6«7 

5*-7 

4 

2643 

47i*3® 

Not  Tested 

F.A.  (Substi- 
tuted for 
(Berdan) 

*9J>  , 

.N'o  test;  National  Mati^  Ammunition  Used. 

Nationa] 
Match  Used 

Hatchkr's  Noteboca 


Random  Notes  on  Various  Subjects 


393 


5.  Nadoiial  Match  Pistol  Ammunition 

The  Pistol  Ammunition  furnished  for  the  National  Matches  during 
the  period  under  discussion  was  loaded  to  the  regular  service  specifica- 
tions calling  for  a 230  grain  bullet  loaded  to  a muzzle  velocity  of 
810  feet  per  second.  In  the  early  years  die  bullets  were  jacketed  with 
Cupro-nickcl;  later  with  gilding  metal. 

A typical  load  was  that  of  the  1929  National  Match  pistol  cartridge, 
which  had  a charge  cif  4-7  grains  of  Bullscyc  Powder,  giving  an  in- 
strumental velocity  at  25  fecc  of  816  feci  per  second,  with  a mean 
pressure  of  14,853  pounds  per  square  inch,  and  n mavimum  pressure  of 
r 6,53  3 pounds  per  square  inch. 

There  were  no  matches  in  1926.  In  192K,  the  1927  ammunition  was 
used.  Accuracy  figures  for  the  years  when  tests  were  held  were  as 
follows: 


yetTf  Group  Dtametcr  at  50  yards 


1020  1.1  S inches 


J92t 

3S5 

igii 

;iWS 

1923 

3.22 

1924 

3.78 

lOiS 

^927 

J-8.? 

1920 

1930 

2.15 

1930 

2.27 

m 

u 

H 

H 

*'  (ll'cstem  Cartridge  Co.) 
**  (Franklord  Arsenal) 


6.  Dimensions  of  Cartridges 

'The  standard  overall  length  of  tlic  service  cartridge  is  3.300  to 
3.350  inches.  In  making  up  anmuinition  to  be  entered  in  the  National, 
iritcrnatiunal  and  Palma  Match  Amimmition  rests,  Frankford  Arsenal 
endeavored  to  adjust  the  overall  length  so  as  to  gain  accuracy  where 
po.ssible  by  crowding  the  bullet  up  closer  to  the  origin  of  the  rifling. 
The  following  shows  the  overall  length  specifications  to  which  these 
cartridges  were  loaded  for  the  years  given. 


Overall  length,  Overall  length,  Intemadonal 

Year  Kaiional  Match  Ammuninon  and  Palma  Match  Ammunition 


1921  Flat  Base,  3.337  to  3.347  inches 
192:  Flat  Base,  3.337  to  3.347  mches 

1922  Boat  Tail  3.337  to  3.347  inches 

1923  Boat  Tail  3.317  to  3.347  inches 

1924  Boat  Tail  3.317  to  3.350  inches 

1925  Boat  Tail  3.317  to  3-350  inches 


Flat  Base,  3.350  to  3.360  inches 
Flar  Base.  3400  to  34^0  inches 
Boat  *1  ail  3.350  to  3.360  inches 
Boat  Tall  3.350  ro  3.360  inches 
Boat  Tail  3.390  ro  3.400  inches 
Boar  Tail  3.390  to  3400  inches 


Hatcher’s  Noteboor 


394 

These  are  some  dimensions  of  the  .30  caliber  Mi  cartridge. 

Weight  of  bullet,  about  152  gnins. 

Weight  of  powder,  49  to  51  grains. 

Weight  of  primed  case,  200  grains  approximately. 

Cubic  capacity  of  case: 

To  shoulder  3.70  c£,  .zi6  cu.  in. 

To  neck  3.95  c-c.  .241  cu.  in. 

To  top  4^0  cx-  .2^  cu.  in. 


7.  Accuracy  Specifications 

Accuracy  Specifications  used  in  World  War  11  for  the  purchase 
of  Caliber  .30  Ball,  Mi,  and  Caliber  .30  Armor  Piercing,  Mi. 


Ammunition 

Type 

Range  at 
which  tested 

Mean  Radius 
inches 

Approzmate 
extreme 
spread}  inches 

Cal.  .30  BaU,  Mi 

500  yards 

6.5 

^9 

Cal.  .30  Bali,  M: 

600  yards 

7-5 

Xl'/l 

Cal.  .30  A.P.,  Ml 

500  yards 

9 

Cal.  .30  A.F.,  M2 

600  yards 

10 

30 

8.  Testing  the  Sensitivity  of  Phmers^  Vent  Diameters  of  Berdan  Primers 
The  primer  under  test  is  held  in  a fixture  fitted  with  a firing  pin 
with  point  of  standard  contour  on  which  a ball  is  dropped  as  follows: 


Caliber 

No.  Tested 

We^ht  of  Ball 

lieight  of 
Drop 

Remits 

Required 

.22  ri. 

50  cartridges 

2 02. 

11  in. 

All  fire 

.22  ri. 

50  cartridges 

2 or. 

2 m. 

None  fire 

.30  cal. 

not  less  than  300 

4 ot. 

15  in. 

All  fire 

.30  cal. 

not  less  than  300 

4 ot. 

None  fire 

y^m  Diinnesrr  for  Various  Bcrda/i  Primers 


Nation  or  Make 

Caliber 

Dia.  of  Vents 

Austria 

8 m/m 

/140  to  080  Taper 

British  (Webley) 

455 

.030 

British 

Mark 

VII-  .303 

.U40 

British 

.50 

040 

British 

.276 

.030 

British 

Mark 

VIJ-.305 

.031 

British  (Magnum) 

.303 

.031 

British  (Bid^  Match) 

.303 

Mil 

Belgian 

7.65  Di/m 

.029 

Czechoslovakia 

8 m/m 

.040 

French 

13  m/m 

.031 

French 

8 m/m  Lebel 

JJ3I 

German 

7 m/m 

MIS 

German 

74»  m/m 

MIS 

Holland 

6.5  m/m 

•03 

Italian  • 

6,$  xn/m 

*055 

Siamese 

8 m/m 

.025 

Swiss 

y.y  m/m 

•*>35 

Random  Notrs  on  Various  Subjects 


395 


9.  Nomenclature  of  Cartridge  E>efects 
Primer.  The  prinier  has  fallen  completely  out  of  its  pocket 
when  gun  is  opened  aicer  hiing. 

Battered  Cartridge.  The  cartridge  is  deformed  so  that  it  will  not 
chamber  in  the  gun. 

Drav:  Mark.  Straight  scratch  lengthwise  of  the  case  due  to  some 
foreign  substance  in  the  drawing  dies. 

Dropped  Primer.  Same  as  Blov:n  Primer. 

Gas  Leak.  Black  marks  around  primer  showing  where  gas  has 
escaped. 

Hang  fire.  Discharge  of  cartridge  after  an  appreciable  interval  from 
fall  of  firing  pin  or  hammer.  This  may  be  due  to  a deteriorated  or 
defective  priincr,  or  to  a weak  firing  pin  blow. 

Incipient  Rupture.  Partial  separation  of  the  cartridge  case  in  a cir- 
cumferential direction  above  the  head. 

Inverted  Anvil  Anvil  in  rhe  primer  upside  down.  Will  cause  a mis- 
fire. 

f^amimted  Case.  A case  which  shows  spots  where  the  metal  has 
separated  in  layers  due  to  scaly  inclusions. 

Leaky  Primer,  Escape  of  gas  around  primer  pocket,  indicated  by 
smoky  nmrks  around  primer  cup. 

Light  Blow.  A weak  firing  pin  blow,  insufficient  to  discharge  the 
primer  properly. 

Low  Primer.  A primer  which  ts  iaserced  too  deep  in  its  pocket. 

This  may  result  in  a hangfire  or  a misfire. 

Misfire.  Failure  of  the  primer  to  go  oft  when  struck. 

No  Anvil.  Absence  of  the  anvil  in  the  primer.  Will  caibe  a misfire. 

Pierced  Frimer.  Primer  in  which  firing  pin  point  has  made  a hole 
all  the  way  through. 

Punctured  Primer.  Same  as  Pierced  Prhner. 

Primer  Blow’Back.  Primer  in  which  gas  pressure  has  blown  out 
the  section  opposite  the  firing  pin  hole.  May  be  due  to  a weak  main 
spring  or  to  a firing  pin  which  is  too  light. 

Primer  Leak.  Escape  of  gas  around  primer  pocket. 

Primer  in  Sideways^  A -rather  rare  defect  which  sometimes  occurs 
in  volume  production.  Primer  fails  to  start  Into  its  pocket  straight, 
and  is  crushed  in  sideways. 

Primer  Set-Back.  After  firing  primer  is  partly  out  of  its  seat. 

Rings.  Circular  marks  around  the  case,  due  to  poor  reaming  of 
the  chamber. 

Split  Body.  A longitudinal  crack  in  the  body  of  the  case  near  the 
head.  This  is  a dangerous  defect,  as  it  allows  gas  to  escape  to  the 
rear. 

Split  Neck.  A crack  in  the  neck  of  the  case.  It  is  usually  due  to 
failure  to  anneal  the  neck  sufficiently  to  prevent  season  cracking. 


Hatcher's  Notebow 


396 

Seasm  Crack.  A cracking  which  occurs  in  hard  brass  with  the 
passage  of  time.  Usually  seen  in  cartridges  as  Split  Necks. 

Soft  Head.  Spreading  of  the  head  and  opening  of  the  primer  pocket 
on  firing,  due  to  over  annealing  of  the  licad  of  the  cartridge. 

Stretch.  A visible  strain  extending  around  the  case  above  the  head. 
Usually  due  to  excess  headspace. 

10.  Inttrior  Bailistics 

Tme,  from  the  instant  of  sear  release  to  the  exit  of  the  bullet  is 
made  up  of 

Lock  Time,  that  is,  the  interval  of  time  from  scar  release  until 
the  impact  of  the  firing  pin  on  the  primer. 


OiBgram  smoked  disk  used  in  measuring  Jock  lime. 


Ignition  Time,  the  interval  from  impact  on  primer  until  the  pres- 
sure rises  enough  to  start  the  bullet  from  its  seat. 

Barrel  Time,  that  is  the  interval  from  the  time  the  bullet  starts  to 
leave  its  scat  until  it  reaches  the  mu7j.lc.  For  the  old  .3o-'o6  cartridge 
with  150  grain  bullet  at  1700  f.s.  muzzle  velocity,  the  barrel  rime  has 
been  measured  ac  .o<x»9R  second,  or  just  under  a thousandth  of  a 
second. 

Lock  Time  may  be  calculated  approximately  by  the  following 
formula: 

Let  S ^ length  of  firing  pin  travel, 
f average  weight  of  the  spring, 
m = mass  of  the  firing  pin  --  Vi  mass  of  the  spring, 
c time  pin  takes  to  fall. 


397 


RaNIiU.M  us  \ AKHK  S Sl  RjKClS 


Then  S = 


and  t 


2 m 


(Kem,  Aberdeen  VrovtJig  Oroimd) 


Actual  lock  time  of  the  ;\!  1903  rifle  was  measured  by  John  C. 
Garand  at  Springfield  Arniory,  using  a smoked  disc,  turning  at  the 
race  of  3057  revolutions  per  minute.  The  firing  pin  was  mounted 
alongside  this  disc,  with  a wire  pointer  attached  to  die  cocking  piece 
so  as  to  touch  the  smoked  surface  of  the  rotating  disc. 


Oarand  ^uper-speed  firing;  mechanism. 


With  the  gun  cocked,  this  wire  traced  a circle  on  the  smoke  surface. 
When  the  trigger  was  pulled,  the  wire  moved  forward  co  the  new 
position  and  there  traced  a 'new  circle  of  smaller  diameter.  Tlie 
angular  length  of  the  spiral  connecting  these  two  circles  indicated 
the  time  of  fall  through  the  firing  pin  travel  of  .6  inch. 

The  time  of  fall  of  the  service  firing  pin  was  .0057  second,  and 
of  the  National  Match  headless  firing  pin,  .0049  second. 


\ I.VI  CHEB’s  NoitiBOCWv 


398 

Mr.  Garand  designed  a speed  tiring  pin  with  a travel  of  only  .4 
inch  that  had  a time  of  fall  of  .0022  second. 

A spring  of  sufficient  strength  was  obtained  by  using  special 
Chrome  Vanadium  steel  wire  which  when  wound,  had  a square 
cross  section,  and  which  was  worked  to  its  maximum  by  having  it 
compressed  solid  w'hcn  the  mechanism  was  cocked. 

To  compensate  for  the  distortion  of  the  wire  in  winding,  it  was 
made  with  one  edge  w'idcr  chan  the  ocher,  a sort  of  keystone  shape. 
When  wound,  the  section  became  square. 

11.  Muzzle  Velocity  vs.  Position  of  Cartridge  When  Loading 

When  the  powder  does  not  competely  fill  the  cartridge  case,  the 
velocity  will  vary  depending  on  w'hecher  the  bulk  of  the  powder 
is  nearer  the  primer  end  or  the  bullet  end  of  the  case. 

If  the  cartridge  is  held  with  the  primer  down  before  loading,  the 
bulk  of  the  powder  will  be  near  the  primer,  and  the  velocity  will 
be  greater. 

If  it  is  held  with  primer  up,  the  powder  will  be  in  the  bullet  end 
of  the  case,  and  the  velocity  will  be  less. 

If  the  cartridge  is  held  horizontally  and  rolled,  the  powder  will 
be  distributed  along  the  length  of  the  case,  .ind  the  velocity  will  be 
intermediate. 

A test  at  Frankford  Arsenal  with  Ql.  .50  Mi  ammunition  also  with 
Cal.  .30  Ml  ammunition  with  lyx  grain  boat  tailed  bullet,  gave  the 
following  results: 


Caliber  Mt 


Mean 
Vcloci^* 
at  78  ft. 

Kstrcnjc 

Variation 

Mean 

V'ariatioii 

Mean  Pressure 

Primer  Down 

2549  Le. 

fji. 

24.2  f.s, 

48.602  Ihs.  per  sq.  in. 

Rolled 

25:4  f.s. 

10^.9  f.5. 

24.6  is. 

47,019  lbs.  per  sq.  in. 

Primer  Up 

2476  f.s. 

95.0  f-S. 

25.3  f.s. 

44461  lbs.  per  sq.  in. 

Caliber 

.^0  Ml.  494  grams  IMR 

Primer  Down 

2611  f.s. 

40.1  is. 

II.I  f4. 

47,387  lbs.  pec  sq.  in. 

Rolled 

2589  f.5. 

61.2  f5. 

154  f.s. 

45,128  lbs.  per  sq.  m. 

Primer  Up 

2567  f.S- 

+M  f-s. 

11.3  f.s. 

43,856  lbs.  per  sq.  in. 

12.  Effect  of  Variatioos  in  Powder  Temperature  on  Muzzle  Velocity 
Velocities  and  pressures  taken  with  a given  charge  of  powder 
and  weight  of  projectile  vary  with  the  temperature  of  the  gun  and 
powder. 

The  standard  temperature  is  tak«i  as  70  degrees  F.  When  the 
gun  and  powder  are  warmer  than  this,  the  velocity  will  be  higher, 
when  they  are  cooler,  the  velocity  will  be  lower. 


Ranijom  N<ri>:s  on  \ aruius  Srnji  crs  399 

The  amounc  of  die  change  depends  on  several  variables,  but  can 
be  approximated  from  the  curve  given  herewith,  as  developed  by 
the  Ordnance  Deparonent. 

Figures  which  have  been  i|uoted  by  various  authorities  for  this 
variation  are  shown  below. 


Gun 

Range 

1 

Correction 

Range  of 
Powder  temp- 
erature used 

Authority 

7 min 

7.9  mm 

7.9  mm 
.30-’o6 
-30-06 
•30-’o6 
.30-’o6 

50  meters 
50  meters 
50  meters 
150  ft. 
150  ft. 
150  ft. 
150  ft. 

i.64  (hS.  pur  degree  P. 
(.09  i.$.  per  degree  F. 
.91  f4».  |>er  degree  F.' 
1.66  is,  per  degree  F. 
r.75  fs.  per  degree  F. 

f3.  per  degree  F. 
1.55  is.  per  degree  FJ 

57  CO  89  deg.  F. 
not  given 
m»t  given 
not  given 
;o  to  140  deg.  F. 
15  to  105  deg.  F 
70  to  .50  deg.  F 

• Pachmann&  Wur/.le 
*Prof.  Brunswig 
Polish  Ord.  Dept. 

U.  S.  Ord.  Dept. 
Frjukford  -Arsenal 
Burnside  Laboratory 
Burnside  Laboratory 

• If7  y.fitschrift  jUr  das  i^esatMpt  Schiass  und  Spren^ssoff  Jan,  1918. 


13.  Distribution  of  the  Heat  Energy  of  the  Powder 
Kacli  pound  of  modem  single  base  smokeless  powder  has  a poten- 
tial energy  of  about  foot  pounds.  If  this  powder  is  fired 

in  a .30  caliber  rifle,  it  will  supply  charges  for  about  140  cartridges, 
and  each  will  6re  a 150  grain  bullet  at  2800  feet  per  second  muzdc 
velocity,  with  a muzzle  energy  of  2d  12  foot-pounds. 

The  amounc  of  this  powder  potential  chat  has  appeared  in  the 
form  of  muzzle  energy  of  the  bullets  is  therefore  140  x 2612,  or 
365,680  foot-pounds,  or  only  about  29*4  percent.  Where  did  the 
other  70%  percent  go  to? 

In  1929  the  Ordnance  Department  set  up  a Technical  Staff  Test 
Program  to  determine  this.  The  firing  was  done  in  a Browning 
Machine  Rifle,  with  results  a.s  follows: 

Heat  distribution  of  one  round  in  a Brown in«  Machine  Rifle. 


Heat  to  Cartridge  Case  1310  B.T.U. 

To  Kinetic  Energy  of  Bullet  885.3  B.T.U. 

To  Kinetic  Energy  of  Cases  569.1  B.T.U. 

Heat  to  Barrel  679.9  B.T.U. 

Heat  in  Gases  598.6  B.T.U. 

Total  28640  B.T.U. 

Heat  Generated  by  Fnctbin  2i2j>  B.T.U. 


14.  Velocity  vs.  Barrel  Length 

Tcics  made  at  Springfield  Annorv  with  various  length  barrels  for 
the  Browning  Machine  Gun  gave  the  following  comparative  figures: 


Length  Barrel, 
Inches 

.30  CaJ.  ’06, 
Velocity,  F.S. 

.50  Caliber, 
Vclocirv,  F.S. 

24 

2709 

2444-9 

28 

2776 

2567 

W 

2833 

2673.9 

32 

28^ 

2702 

400  Hatcsirr’s  Notkbook 

The  1917  Enfield  rifle  with  26  ioch  barrel  gave  for  an  average  of 
five  shoes  each  with  2 barrels,  2783  f.s.  vs.  2700  for  the  1903  rifle 
with  24  inch  barrel. 


15.  Comparative  Table  of  Remauung  Velodcies,  Energies  and  Form  Factors 

for  .50  and  50  Caliber  Ammunition.* 


Range 

j 

iQnrt  Ball  Service 

170  Gr. 

Fbt  Base 

Experimental 
1912  170  grain 
6 deg.  Boat  Tail 

yards 

Remaining 

Remaining 

Remakiing 

Remain  ing 

Remaining 

Remaining 

Vclocicv 

F-nergy 

Velocity 

Ejie^y 

elocicy 

Energy 

f/s 

1 Ft.  lbs. 

f/s 

Ft.  lbs. 

f/s 

Kc.  lbs. 

n 

2700 

1429 

2700 

J75J 

2700 

2753 

^QO 

1240 

1506 

860 

*777 

1197 

(OOO 

958 

306 

1083 

444 

1303 

644 

1500 

763 

(94 

815 

1 

960 

349 

2000 

”4 

62H 

1 C49 

777 

219 

2500 

408 

55 

4/i 

84 

638 

*54 

^XemaMng  Velociryt  Rangi,  and  Energy  of  172  grain  Cal.  A.  P.  and  Ball 
Ammunition  and  7/0  grain  Cal.  .so  A.  P.  and  Ball  A?miuniHon  Mt, 


Remaining 

Velocity 

Range— yards 
Cal.  .30  Cal.  .fo 

Energy- 
Oil.  .30 

-ft.  lb. 

Cal.  .50 

2600 

26 

4 4 * • 

2562 

2500 

79 

26 

2388 

1041 1 

2400 

*34 

11^ 

2200 

9595 

2300 

(91 

209 

2021 

B812 

2200 

^49 

304 

1849 

B062 

2100 

310 

403 

1665 

7346 

2000 

37* 

505 

1528 

6663 

1900 

43^ 

6u 

*379 

60C4 

1800 

503 

721 

1238 

5397 

1700 

S7S 

836 

1104 

4814 

1600 

^48 

95h 

97K 

4264 

1500 

7^7 

1088 

860 

3748,;?=^ 

1400 

8l2 

1227 

749 

1300 

905 

1379 

648 

2815 

1200 

1014 

1538 

55« 

2399 

1100 

1161 

*799 

462 

ZOI6 

1000 

»37* 

2'4> 

382 

1666 

After  the  adoption  in  1925  of  the  Mi  ammunition  containing  the 
172  grain  boat-tailed  bullet,  an  investigation  was  made  to  determine 
the  form  factor  for  use  with  Ingalls  ^llisric  Tables,  Artillery  Cir- 
cular M.  Results  are  shown  below: 


* (Coniputed  from  Tngall’s  Tables,  using  dara  fmm  unredxiced  firings  made  ar 
Aberdeen  Proving  Ground,  Md.,  between  Nov.  22,  and  Dec.  22,  1922.) 


Random  Notes  on  Various  Subjects  40 j 


1‘ablc  of  form  factors  for  i^z  graw  boat-ia'ded  buiUt  Cal.  .30  Mt 


Velocity,  feet  per  second 

Form  Factor 

2600 

492 

2000 

•5*4 

1500 

.568 

1200 

•744 

]6.  Balljsric  Data 

Pedersen  Rifle,  Caliber  .276,  (D.276-A-2  J 

125  Gr.  Bullet— P.  C.  4K,  (A.  P.  G. 

Instrumental  Velocity  at  78  feet  = 2640  f/s  (Aug.  25,  1927 

B.  C.  for  J (v)  5=  D.2469  when  V is  greater  than  vcl.  of  sound 

0.4260  when  V is  less  than  vel.  of  sound 


Range 

Yards 

Angle  of 
Departure  : 
Minutes  ; 

Time  of 
Fl%ht 
Seconds 

Remaining 

Maximum 

Ordinate 

Feet 

Velocity 

ft/s 

Fnergy 

ft-lbs 

0 

0.0 

0.000 

2690 

2012 

.00 

too 

*•3 

.115 

M'4 

1758 

.07 

100 

5*0 

.229 

J529 

8.0 

•)7i 

f 180 

J322 

•57 

400 

(1.2 

•5*4 

2020 

**35 

T.09 

500 

14.6 

.669 

1864 

966 

1.82 

600 

18.7 

1711 

814 

1 *.84 

700 

IJJ 

1.021 

1562 

679 

4.21 

800 

26.1 

1.222 

1419 

560 

6.00 

900 

‘444 

12S4 

459 

8.27 

1000 

40.5 

1.691 

1 160 

374 

**•54 

1 

1100 

48.1 

1.960 

108) 

3*7 

*544 

1200 

56.8 

2.242 

1046 

304 

20.63 

Caliber  .30  Rvillcc,  1906  Service  Anittiunition,  (A.  P.  G.,  Md. 

M.  V,  2700  f/s.  C V'ariablc,  starting  widi  0.4 to.  (April^^26 

(H-j‘^/,28 


Range 

Yards 

Angle  of 
Departure 
Minutes 

TiJiic  of 
Flight 

Secon<l2i 

Remaining 

Alaximum 

Ordinate 

Feet 

Vclocitv  1 
ft/s 

Knetgy 

ft-lbs 

100 

*•5 

0.12 

2481 

1 ^®5* 

0.06 

200 

5.2 

0.25 

1 2267 

0.27 

300 

8.2 

0.38 

2059 

■HH 

0.62 

400 

(1,6 

1 0*53  1 

; 'M 

1150 

1.1 

500 

15.6 

1 0*7®  1 

1 '*4 

9*3 

2X) 

600 

204 

0.89 

1 *4^* 

7}I 

$•3 

700 

*5-9 

i.ii 

*3«5 

576 

800 

n-s 

2-35 

1174 

459 

74 

900 

40^3 

1.62 

1065 

378 

10.8 

1000 

494 

*•9* 

989 

326 

15.2 

402 


I Iatt^hkr’s  Ni»TFBOOK 


U.  S.  Caliber  .30  Mi  (0.30-B-4 

172  Gr.  Bullet,  Muzzle  Velocity  2600  f/s  {A.  P.  G. 

B.  C.  for  J (v)  Table  = 0.2702  when  V is  greater  (Sept.  7,  1927 

than  vel.  of  sound 

0.3977  w^hcn  V is  less  than  vel  of  srmiid 


Range 

Yards 

Angle  of 
Depairurc 
M mutes 

lime  of 
Flight 
ScciHids 

Remaining 

Maximum 

Ordinate 

Feet 

Vdoocy 

fc/s 

Energy 

fc-lbs 

0 

OJO 

2600 

OX) 

100 

»*5 

0.J19 

1 

2442 

O.I 

200 

5^3 

0.246 

2289  1 

2002 

0.3 

300 

8.4 

o.)8i 

2140 

1750 

0.6 

400 

11.8 

0.527 

2995  1 

1520 

1.1 

500 

15,4 

0.683 

1852 

1311 

*9 

600 

194 

0.831 

nn 

U20 

2-9 

700 

2)9 

1.034 

1576 

949 

4*3 

800 

29.0 

1.235 

*444 

797 

6.1 

900 

, 34*7 

1450 

1320 

66s 

8.5 

1000 

1 

uS88 

ItO) 

553 

116 

1100 

48^ 

*•949 

1101 

464 

*54 

noo 

1 57-0 

2.u8  1 

1057 

427 

20.3 

U.  S.  Caliber  .30  Mi  (0.30-B-3 

172  Gr.  Bullet,  Muzzle  Velocity  2700  f/s  , P.  G. 

B.  C.  for  J (v)  Table  = 0.2702  when  V'  is  greater  '^pt.  7,  1927 

than  vel.  of  sound 

0.3977  when  V is  less  than  vel.  of  sound 


Range 

Yards 

Angle  of 
Departure 
Minutes 

Time  of 
Flight 
Seconds 

Renuining  ' 

Maximum 

Ordinate 

Feet 

Velocity 

ft/s 

Energy 

ft-lbs 

1 

0 

0.0 

0.000 

2700 

M 

CD 

OX) 

too 

2-3 

0.1 15 

2539  1 

1463 

O.I 

200 

4.9 

0.237 

2384  , 

2170 

0.3 

300 

7*7 

0.367 

1232 

1903 

0.6 

400 

10.8 

0.506 

2084 

1660 

i.i 

500 

14.1 

o£ss 

1940 

143B 

1.8 

600 

17.9 

oSi$ 

1799 

*257 

2.8 

700 

22.0 

o-9*9 

i6te 

*053 

4‘* 

800 

26.7 

IJ77 

1526 

889 

5.8 

900 

3*-9 

i.j8j 

IJ97 

745 

7«9 

(OOQ 

37-7 

iiSo8 

>*75 

621 

10.5 

1100 

44*3 

1^55 

1161 

5*5 

>3-9 

1200 

52x3 

2.134 

1083 

448 

18.3 

Random  Kmiis  on  Various  Subjecis  403 

17.  Rule  for  Computing  Or<Unjitcs  to  Trajectory 

l>et  y ~ height  of  desired  ordinate  in  yards 
X = horizontal  distance  to  desired  ordinate 
Ar « angle  of  departure  in  mils  for  die  trajectory  being  computed 
Ax  — angle  of  departure  in  mils  for  the  range  corresponding  to  x 

Then  y = — — (A,  — Ax) 

^ 1000 

Example: 

Wanted,  the  1000  yard  ordinate  of  the  2000  yard  trajectory* 
Given,  Ar  “ angle  of  departure  for  louo  yards  = 44.5  niifs. 

Ax  — angle  of  departure  for  1000  yards  *=  tr.i  mils. 

-ru  / V 

>’ 

Note— A mil  is  3*575  minutes. 


IS.  Formub  foe  Wind  Dtfiection 

Let  D = deflection  of  the  bullet  in  feet  caused  by  wind. 

W = wind  velocity  straight  across  the  range  in  feet  per  second. 
If  the  wind  is  not  straight  across  the  range,  then  that 
component  of  it  which  acts  straight  across  the  i*ange  at 
right  a^les  to  the  line  of  sight. 

T = time  of  flTghc  in  seconds  for  the  range  at  which  the  de- 
flection is  to  be  figured. 

Tv  = time  it  would  take  the  bullet  to  traverse  the  same  distance 
in  a vacuum. 

Then  D ^ W (T^Tv) 

Example;  Find  the  deflection  that  would  be  caused  at  various  ranges 
by  a wind  of  1 mile  per  hour  acting  on  the  172  grain  Mi 
boatcail  bullet  with  an  initial  velocity  of  2700  feet  per 
second. 

Renicniber— I mile  per  hour  — 1.4667  feet  per  second. 


Range. 

yards. 

Time  of 
Hight. 

rime  to 
cover  same 
range  in 
vacuom. 

Ditfcrciice 

DefUcuoh, 

feet 

Deflection. 

inches. 

iOO 

.C15 

.Ill 

.006 

•07 

100 

.2Z2 

JJ15 

X>22 

.26 

^00 

.367 

.OJ4 

.050 

.60 

400 

.506 

•444 

j)6i 

-091 

1.09 

500 

.665 

•555 

.100 

•«47 

1.76 

600 

.8ty 

iS67 

.148 

-217 

2.60 

700 

-989 

.778 

.2X1 

.309 

3-7* 

800 

1.117 

.889 

.288 

•4*2 

5.06 

900 

1.383 

ixno 

.383 

.562 

6.74 

cooo 

1.608 

x.iii 

•497 

►7*9 

8.75 

404 


Hatcher’s  Notebook 


19.  The  Relation  Between  Velocity  and  Instnimental  Velocity 

When  velocities  arc  taken  by  chronograph,  what  is  obtained  is  not 
the  muzzle  velocity,  hut  instead,  the  velocity  over  a measured  interval 
somewhere  in  front  of  the  mn7zlc. 

At  Springfield  Armory,  Frankfort!  Arsenal  and  Aberdeen  Proving 
Ground,  it  is  usual  when  taking  the  velocities  of  small  arms  ammiini- 
don  to  measure  the  rime  taken  to  pass  between  two  screens  either 
loo  or  150  feet  apart.  The  first  screen  is  usually  placed  3 feet  in  front 
of  the  muzzle  to  avoid  blast  effects. 

The  time  taken  to  traverse  the  distance  between  screens,  divided 
by  this  distance  gives  the  average  velocity  from  chc  first  screen  to  the 
second. 

The  bullet  is  going  faster  when  it  passes  the  first  screen  than  it  is 
when  it  reaches  the  second,  but  it  may  be  assumed  without  much 
error  that  the  average  velocity  between  screens  represents  the  ve 
locity  at  a point  hal^ay  between  the  two  screens. 

Thus  with  the  first  screen  three  feet  from  the  muzzle  and  the 
second  100  feet  from  the  first,  the  velocity  obtained  is  that  at  53 
feet  from  the  muzzle.  With  the  first  screen  efiree  feet  from  the  mu'/zle 
and  the  second  screen  150  feet  further  along,  the  instrumental  velocity 
obtained  is  that  zt  jH  feet  from  the  muzzle. 

For  velocities  in  the  order  of  those  obtained  with  chc  service  ammu- 
nition it  has  been  found  with  standard  atmospheric  density  condi- 
tions the  speed  drops  off  at  the  rare  of  -64  foot  per  second  /nr  every 
foot  from  the  muzzle  to  the  mid  point  between  screens. 

Thus  to  find  the  muzzle  velocity,  given  the  instrumental  velocity^ 
at  78  feet,  we  should  add  to  the  instrumental  velocity  an  amount 
equal  to  78  x .64,  or  49*92  feet,  which  is  taken  as  50  feet,  per  second. 

Likewise,  to  bring  chc  instrumental  velocity  at  53  feet  to  muzzle 
velocity  we  should  add  53  x .64  or  33*92.  that  Is,  34  feet  per  second. 

If  very  accurate  results  must  be  had,  these  figures  should  be  cor- 
rected for  any  variation  of  the  atmospheric  density  from  the  normal, 
which  is  considered  as  1.2034  p*^ms  per  liter. 

The  ratio  of  the  density  of  the  air  at  the  time  of  firing  to  the 
normal  density  is  designated  by  die  Greek  letter  Rho;  let’s  call  it 
*‘r”.  Then  Muzzle  Velocity  = Instrumental  Velocity  + .64  x s x r, 
where  s is  the  distance  in  feet  from  the  muzzle  to  the  mid  point  be- 
tween screens. 

For  values  of  Rho  see  table  on  page  430. 

20.  Mils  Versus  Minutes 

Li  small  arms  target  practice  it  is  usual  to  give  elevations  in 
minutes  of  angle,  which  is  convenient,  as  a minute  equals  very  nearly 
an  inch  for  every  hundred  yards  of  the  range.  Thus  a minute  of 
elevation  change  on  the  rear  sight  should  raise  or  lower  the  point 
of  impact  an  inch  at  too  yards  or  ten  inches  at  1000  yards. 


Random  Notes  on  Various  Subjects  405 

In  military  lire  control  work  it  is  usual  to  ust  a different  unit, 
the  mil  The  mil  is  the  angle  whose  tangent  is  i/iooo;  that  is,  it  is 
the  angle  subtended  by  i unit  at  a distance  of  looo  units^  for  ex- 
ample, I foot  at  1000  feet  or  1 yard  at  1000  yards. 

This  would  work  out  so  that  there  arc  <^183  mils  in  a complete 
circle.  As  this  number  is  not  divisible  into  fractions  winch  arc  whole 
numbers,  the  artillery  rtre  control  experts  adopted  the  artillery  mil, 
in  which  the  circle  was  divided  into  6^tjo  parts,  thus  giving  a number 
which  is  easily  divisible  by  many  other  numbers,  and  still  not  chang- 
ing the  value  of  the  mil  to  any  sensible  degree. 

For  some  years  the  infantry  used  a mil  of  i /6280th  of  a circle, 
called  die  Infantry  mil,  while  the  Artillery  used  i /64ootli  of  a circle, 
called  the  Arcillcry  mil. 

In  recent  years,  however,  the  so-called  Infantry  mil  has  been 
draped  from  use,  and  the  Artillery  mil  adopted  in  its  place. 

The  Artillery  mil  is  j'  21.5"  of  arc,  or  3.375  minutes.  As  rifle 
elevations  are  given  in  the  technical  manuals  in  mils,  this  is  a useful 
number  to  know.  To  reduce  mils  to  minutes,  multiply  by  3-375. 


21.  Comparison  of  Angies  of  Departure  (A[^m>x)  of  Caliber  .30  Ball 
Ml  At  Ground  Level  and  at  Elevadou  10,000  ft. 

Kangc 

Angle  Dep.  Mils 
Kiev.  10,000  ft. 

Angle  Dei).  Mils 
Ground  Level 

Drift  Right  Mils 

Yards 

Anglo  of  site  0 

(Ground  l^vel) 

0 

0 

0 

0 

100 

0-7 

0-7 

0 

200 

«-5 

1*5 

u 

3W1 

2.2 

*•4 

0 

40Q 

i-3 

0 

500 

3-9 

4*3 

0 

600 

4-7 

53 

0 

700 

6.5 

0 

800 

7-ft 

0 

900 

7-0 

9-3 

0 

tooo 

II. 1 

0 

[too 

)0.2 

13.1 

0 

1200 

1 us 

154 

o.t 

t|00 

15*5 

18.0 

0.1 

I4UO 

15.J 

20.7 

O.I 

1500 

17*3 

*3-9 

0.1 

1<K>0 

197 

*7-3 

0.2 

t?oo 

22.J 

3>d 

0.2 

tOoo 

25.J 

0.2 

1900 

0.3 

2000 

V-7 

44-3 

0.5 

22.  Bullet  Penetralion  in  Various  Mediums 
The  Ordnance  Ekpartmenr,  U.  S.  Army  determined  chat  the  150 
grain  M2  service  bullet  fired  into  water  with  a velocity*  of  2770  f.  s. 


Pcneifalioo  of  32V2  of  oak  by  .3l)-’06  bullet  weigh  log  grains,  driven  ai  a mtizzlc  velocity  of  2 TOO  f.s.  Range,  200  yards. 

The  range  was  long  enough  so  that  the  bullet  was  suffidcodv  stabilized  to  continue  point  hr»t  ami  thus  give  good  penetration.  At 
shorter  ranges,  the  penerratinn  ts  likcK  to  be  much  less — s«  photo  showing  results  ac  50  Icei. 


Penetra i ion  of  1 1 V i • o c h in  09 k *30^  1 50  bulic  I <lf  ivcn  ji(  2^00  50  feet*  The  p to ci ration  is  much  Ic^s 

than  that  achieved  at  longet  ranges.  The  tea^m  U that  at  this  »h«irt  ran^te,  the  hullec  had  not  ‘sefiled  down  to  a 'Stable  flight,  and 

when  it  cncuuniered  the  resistance  of  the  oak  it  yawpd  badly,  and  rapidly  gave  up  all  its  energv. 


Hatchers  Notebooic 


408 

a:  an  angle  of  incidence  of  90  degrees  would  be  flowed  to  140  feci 
per  second  at  3 Yz  feec  below  the  surface  of  the  water.  At  this  velocity 
the  energy  is  100  foot-pounds,  which  is  considered  the  minimum  to 
inflict  a wound  on  the  human  body.  Therefore  a man  would  be  safe 
from  strafing  with  .30  caliber  ballets  if  be  were  4 feet  beneath  the 
surface. 

The  Navy  Hureau  of  Ordnance  determined,  based  on  tests  made 
at  the  Naval  Proving  Ground  at  Oahlgrcn,  Va.,  that  a man  would 
be  safe  under  354  to  4 feet  of  water  imiu  a .}o-n6  projectile  fired 
at  an  angle  of  incidence  of  90  degrees  to  the  water,  and  that  at  an 
angle  of  incidence  of  30  degrees,  which  would  be  more  nearly  the 
angle  at  which  a plane  would  attack  a man,  a man  lYi  feet  beneath 
the  surface  would  be  safe. 


Penetration  for  Cal.  .30  M i Ammunition 


200 

yards 

600  yards 

1^00  yards 

Aver- 

age 

Maxi- 

mum 

Aver- 

age 

Maxi- 

mum 

Aver- 

age 

Maxi- 

mum 

1/4"  Armor 

0.1" 

• 4 • % 

4 # e ♦ 

1 a • a 

4 4 4 t 

Gravel 

8.0" 

4-y 

Brick  masonry 

l-t 

^•5 

(9 

Concrete 

4-0" 

t.0 

*494 

0.; 

$444 

Solid  Oak 

T3.8’' 

i8.o" 

12.0 

2.1 

3.8 

Dry  Sand 

d.5" 

8.2" 

71 

8.5 

8.2 

9-0 

Moisc  Sand 

7*5 

9.1" 

tl.2 

8.7 

9^5 

r.oam 

24.1" 

24 

i$a 

26.2 

Clay 

24.6^ 

29.0 

22.0 

2J.0 

14.0 

15X) 

Loose  Earth 

C9.0" 

15.8 

4 4 4^ 

k 4 4 4 

» • « 1 

23.  Bullet  Lubricant  Formulae* 


No.  / 

Ya  pound  Japan  Wax 
2 heaping  teaspoons  Graphite 
(Graphite  must  be  mechanically 
mixed  and  therefore  it  must  be 
very  fine,  like  Acheson  Graphite 
No.  1304  or  Dixon’s  Motor  Gra- 
phite) 


No.  2 

Equal  parts  of  Beeswax  and  Car- 
miba  of  Japan  Wax,  Cylinder  Oil 
or  Castor  Oil,  just  enough  to  bring 
required  flex i bilk v 


Our  own  lubricant  consists  of  equal  parts  beeswax  and  paraffin 
tempered  to  a tough  pliable  consistency,  bv  the  trial  and  error  method, 
using  vaseJine,  or  a good  grade  of  cup  grease  such  as  Pennzoil  No.  305 
which  contains  graphite.  Add  fine  powdered  graphite  if  you  want 
a black  lubricant. 

While  the  waxes  arc  melted  we  add  about  25%  as  much  grease 
by  volume.  Then  several  samples  are  “rested”  for  consistency  by 


From  the  National  Rifle  Aasociatinn  Teriinical  Srafl. 


Random  Notes  ok  Various  Subjects  409 

Ictdng  one  sample  cool  ac  rootn  cempeiacure,  and  the  other,  in  a 
shallow  pan,  is  cooled  in  the  refrigerator.  If  the  mixture  is  very 
brittle  when  cool  we  add  more  grease,  or  more  wax  if  too  soft.  Our 
mixture  is  used  on  both  rifle  and  handgun  bullets,  and  we  never 
experience  leading  trouble.  Our  alloy  consists  of  96  parts  lead,  2 
pans  tin  and  2 parts  andmony. 

24.  IndendlicatioD  Codes  ol  German  Arms,  Ammiinitioa  and  Optical 

Instruineot  Makers 

During  the  occupation  of  Germany  immediarcly  after  V.  E.  Day 
in  1945,  our  forces  obtained  a secret  German  document  giving  the 
identification  code  letters  of  various  makers  of  arms,  ammunition  and 
optical  instruments. 

The  document  appeared  soniewhac  garbled,  and  there  were  some 
duplications,  indicating  chat  some  changes  had  been  made  from  time 
to  time. 

Even  though  the  list  may  be  incomplete,  it  has  proved  to  be  very 
useful,  as  the  makers  whose  products  arc  most  often  seen  among  the 
souvenir  weapons  brought  back  from  Europe  appear  on  this  list. 

German  Small  Arms  Manufacturers'  Codes 

A 

aak-Waffen/abrik  Brunn  A.  G.,  Prague 

aC’Carl  Walcher,  2ella-Mehlis,  Thuringia 

ack-F.  Uusck  Waflenerzeuguitg,  Opocznb  bei  Nachod 

amn-Mauser  Works,  Waldeck  bei  Kassel 

ar^Mauser  Works,  Bursigwatde,  Berlin 

ash-nciitsche-Waffcn  und  Munitions  Fabriken  A.  G.,  Borsigwaldc, 
Berlin 

auc-Mauser  Works  A.  G.,  Ehrenfeld,  Cologne 
awc-Wurttembergische  Metallwarcnfabrik  A.  C».,  Geislingen 
axs-Bemdorfer  Metallwarcnfabrik  Arthur  Knipp  A.  G.,  Berndorf, 
Niederdonau 

ayf-B.  Geipel,  G.  m.  b.  H.,  Waffenfabrik  Trma'* 
azg-Siemens-Schuckert  Works  A.  G.,  Berlin 

B 

bed-Gusdoff  Co.,  Weimar  Works,  Weimar 

be-Berndorfer  Metallwarcnfabrik  Arthur  Krupp  A.  G.,  Berndorf, 
Niederdonau 

bh-Brunner  Waffenfabrik  A.  G.,  Brunn  (Brno,  Czechoslovakia) 
bjv-Bohm-Malirischc  Kolbcn-Danek  A.  G„  Prague,  Vysocan  Works 
bkp-Gewehrfabrik  H.  Burgsmullcr  and  Sons  G.  m.  b.  H.,  Krcicn- 
sen,  Harz 

bkq-Rohrenfabrik  Johannes  Surmann  G.  m.  b.  H.,  Arnsbe^ 
bky-Bohmische  Waffenfabrik  A.  G.,  of  Prague,  Ung-Brnd  works, 
Ung  Brod,  (Moravia) 


t 


4^0 


Hatcher’s  Notebook 


bmv-Rheininetall-Bor>ig  A.  G.,  Sommerda  Works,  Sommer  da 
bmz-Mmerva  Nahmaschincnfabrik  A.  G.,  Boscowirz 
bnd-M.  A.  N.,  A.  G.,  Niirnberg  Works,  Nurnberg 
bnz-Sceyr-Daimler  Puch  A.  G.,  Steyr  Works,  Steyr,  Austria 
bpr-Johannus  Grossfuss  Merall  and  Locicrwarcnfabrik,  Dobeln, 
Saxony 

br-iMachias  Bauerle  Laufwcrkc  G.  m.  b.  H.,  St,  Georgcn,  Schwarz- 
wald 

bvl-Th.  Bcrgiiiann  & Co.  .Ahteilung  Automatcn  u.  Metallwarcnfab- 
rikation,  Alcona,  Hamburg 
bxb-Skoda  Works,  Pilsen 
byf-Mauser  Works,  Obemdorf 

byni-Genossenschafts  Maschinenhaus  der  Biichsenmacher,  Ferlach, 
Carinthia,  Austria 

bzt-Fritz  Wolf  Gewehrfabrik,  Zella-Mehlis,  Thuringia 

C 

cc-J.  P.  Sauer  and  Sons  Gewehrfabrik,  Suhi,  Saxony 
cdn-Th.  Bergmann  k Co.  A.  G.,  Waffen  ii.  Alunitionfabrik,  Velccni 
Works,  Veltem  am  Main 

ch-Fabrique  Nationale  d’Armes  dc  Guerre,  Herstal,  Liege,  Belgium 
chd-Berlin  Industrie  Werke  A.  G.,  Spandau,  Berlin 
cof-Carl  Eickhorn,  WafFcnfabrik  ^lingen 
con-Franz  Stock  Maschinen  u.  Werkzeufabrik,  Berlin 
cos-Merz  Brothers,  Frankfurt  am  Main 

cpo-Rhcinmetall-Borsig  A,  G.,  Mahcnfeld  Works,  Marienfeld, 
Berlin 

cpp-Rheinmctall-Borsig  A.  G.,  Guben  Works 
cpq-RheinmetaIl‘Borsig  A.  G-,  Breslau  Works 
crs-Paul  Weyersberg  4c  Co.  Waffenfabrik,  SoHngen 
cvI-WKC  Waffenfabrik  G.  m.  b.  H.,  Solingen 
exq-Spreewerk  G.  m.  b.  H.,  Meta Ihvarcn fab rik,  Spandau,  Berlin 

D 

dfb-Guscloff  Co.,  Suhl  Gun  Works,  Suhl,  Saxony 
dgl-Remo  Gewehrfabrik,  Rempt  Brothers.  Snhl,  Saxony 
dor- Waff en werke  Brunn  A.  G.,  Brunn  (Brno,  Chechoslovakia) 
dou-Waffenwerke  Brunn  A.  G.,  Bystrica  Works 
dov-Waffenwerkc  Brunn  A.  G.,  Vsetin  Works  Czechoslovakia 
dow-Opticotechna,  (formerly  Waffenfabrik  Brunn  A.  G.),  Prerau, 
Czechoslovakia 

dph-Intcrcsscn  Gemcinschaft  Farbenindustrie  A.  G.,  Autogen 
Works,  Cjricsheim,  Frankfurt  am  Main 
dsh-Engincer  F.  Janecck,  Gun  Works,  Prague, 
duv-Berliner-Lubeckcr  Maschinenfabriken,  Lubeck  Works 
duw-Deutsche  Rohrewerke  A.  G.,  Tliysscn  Works,  Mtilheim 


Random  Notes  on  Various  Subjects  41 1 

E 

egy -Engineer  Fr.  August  Pfeffer,  Oberlind,  Thuringia 

F 

fnh-Bomische  Waffenfabrik  A.  C.  of  Prague.  Strakonitz  Works 
fue-Mechanische  Wcrkstart  A.  G.,  (formerly  Dnbnica  Works  of 
Skoda  Co.),  Dubnica 

fwh-Norddcutschc  Maschincnfabrik  G.  in.  h.  H.,  Haiiptverwalcing, 
Rerlin 

fxa-Eisenacher  Karosseriefabrik  Assmann  G.  m.  b.  H.,  Eisenach 
f.xo-C.  G.  HaencI  Waffcn  u.  Fahrrad  Fahrik,  Suhl,  Saxony 
fze-F.  W.  Holler  Waffenfabrik,  Soiingen 
fzs-Heinrich  Krieghoff  Waffenfabrik.  Suhl,  Saxony 

G 

ghf-Fritz  Kiess  & Co.,  G.  m.  b.  H,  Waffenfabrik,  Suhl,  Saxony 
gsb-Rhcinmecall-Borsig  A.  G.,  (formerly  S.  A.  dc.s  Ateliers  cie  la 
Dylc),  Louvain,  Belgium 

gse-S.  A,  Beige  de  Mccank|ue  et  de  rArmeincnc,  Monceau-sur- 
Sambre,  Belgium 

guy-Werkzeugniaschincnfabrilc  Oerlikon,  Buhrie  & Co.,  Oerlikon 
Zurich,  Switzerland 

H 

hcw-Eriingecr  F.  Janccck,  Gun  Works,  Prague 
hhg-Rheinmetall-Borsig  A.  G.,  Tegel  W'orks,  Tegel,  Berlin 
hhv-Sceyr-Daimlcr  Puch  A.  G.,  Nibehmgen  Works,  St,  Valentin, 
Austria 

J 

jhv-Mecallwaren  Waffcn  ii.  Maschinenfabrik  A,  G.,  Budapest 
jkg-Kong.  Ungar  Staatlische  Eisen,  Stahl  u.  Maschinenfabrik, 
Budapest 

jl)-Hcere.s  Zeuganir,  Ingoldstadc 

jua-Danuvia  Waffcn  u.  Mnnirionsfabrik  A.  G.,  Budapest 
jwa-Mamifacturc  d’ Amies  Chatclleraulc,  Chatellerault,  France 

K 

kfk-Dansk  Industrie  Syndicat,  Copenhagen,  Denmark 
kls-Stevr-Dainiler  Puch  A.  G..  Warsaw 

ksb-Manufacturc  Nationalc  d\Amies  de  Lcvallois,  Lcvallois,  Paris, 
France 

kur-Steyr-Daimler  Puch  A.  G.,  Graz  Works 
kwn-S.  A.  Fiat,  Turin,  Italy 

L 

Iza-Mauser  Werke  A.  G.,  Werk  Karlsruhe 

M 

moc-Joliann  Springcris  Erbcn  Gewehrfabrikaniea,  Vienna 
mpr-S.  A.  Hispano  Suiza,  Geneva,  Switzerland 


TIatchf.r's  Xotkbook 


4'2 

mrb'Aktieng€sellschafr>  (fonncriy  Prague  Works  of  Skoda  Co,)> 
Prague 

myx-Rheinmctall-Borsig  A.  G.,  Sommerda  Works,  Sommer  da, 
Thuringia 

N 

nec-Waffenwerke  Brunn  A.  G.,  Prague 

nhr-Rheinmetall-Borsig  A.  G.,  Sommerda  Works,  Sommerda, 
Thuringia 

nyv-Rheinmetall  Borsig  A.  G.,  Werk  Unterluss 
nyvv-Gustloff  Co.,  Mciningen 


German  Small  Arms  Avnmam<m  Manufacturers'  Codes 

A 

ad-Patronen,  Zundhiiichen  and  Mecallwarenfalirik  A.  G,,  (formerly 
Sellier  and  Bel  lot),  Schocnbeck  am  Elbe 
ak-Municionsfabriken,  (formerly  Sellier  and  Belloc,  Prague),  Fac- 
cory  at  Vlasim,  Czechoslovakia 

at -Deutsches  Leuchtand  Sign almictel werk,  Dr.  Feiscel  A,  G.,  Berlin- 
C^harlottcnburg 

am-Ocro  Eberhardc  Patronenfabrik,  of  Gustloff  Co.,  Hirtenberg, 
Niederdonau 

an-C.  Beufccnmuller  & Co.,  G.  m.  b.  H.,  Mctallwarenfabrik,  Brettcn, 
Baden 

ap-Otco  Eberhardc  Patronenfabrik,  Ronsdorf  Works,  Wiipperral 
ash-Deutsche  WafFen  and  Munitioasfabriken  A.  G.,  Borsigwalde, 
Berlin 

asr-HAK,  (Hanseacisches  Kettenwerk  G.  m.  b.  H.),  Hamburg 
auu-Patronenhulsen  and  jMctalhvarcnfabrik  A.  G.,  Rokveany, 
Oechoslovakia 
aux-Polte,  Magdeburg  Work.s 
auy-PoIte,  Gruneberg  Works 
auz-Po(tc,  Amstadt  XVorks 
axq-Erfurter  La  den -Industrie,  Erfurt,  Nord 

B 

bqt-Eugen  Miiller,  Pyrotechnic  Works,  Vienna 
byc-Aug.  Klonne,  Bruckenbau  Anscalt,  Dortmund 

C 

cg-Finower  Industrie  G.  m.  b.  H.,  Finow,  Mark 
ch-Fabrique  Nationale  d’Annes  dc  Guerre,  Herstal,  Liege.  Belgium 
cxni-Gustav  Genschow  & Co.  A.  G.,  Berlin 
czo-Heeres  Zeugamt,  Geschosswerkstatt,  Koenigsberg 


4«3 


Random  Notts  ox  V^ARiot’s  Subjects 

D 

dbg-Dynamit  A.  G.,  (formerly  Alfred  Nobel  & Co.)»  Duneberg 
Works 

dma-Heercs‘Munidons  Anstalc^  Geschosswerkstatc,  Zeithatn 
daf-Rheinisch-Westfalischc  Sprcngstoff  A.  G.,  Scadeln  Works, 
Scadeln,  Niirnberg 

dnh-Rheinisch-Wescfalischc  Sproigstoff  A.  G.,  DurUch  Works 
dph-Interessen  Gemeinscafc  Farbenindustric  A.  G.,  Aucngen  Works, 
Greisheim,  Frankfurt  am  Main 

dye-Ed.  Pitsohmarm  & Co.,  Frstc  Alpenlandische  Pyrotechnik,  Inns- 
bruck 

E 

ecc -Oskar  Lunig,  Pyroiechnische  Fabrik,  Mohringen  (Fildcrn) 
ccd-Earl  Lippold,  Pyrorechnlschc  Fabrik,  Wuppertal-Eberfeldc 
cdg-J.  A.  Henckels  Zwillinsgwerk,  Sol  ingen 

edq*Deutsche  Waffen  and  Munitionsubriken  A.  G.,  Lubeck* 
Schlutup 

eeg-Hermann  Weihrauch,  Gewehr  and  Fahrradceilefabrik,  Zdla- 
Mchlis,  Thuringia 

eel-Metallwarcn fabrik,  (formerly  H.  Wissner  A.  G.),  Werk  Broc- 
ccrodc,  Hesscn-Nassaii 

ccm-Selvc-Kornhicge)  Dornlieim  A.  G.,  Munitions  Fabrik,  S6ni- 
tnerda,  Saxony 

eeo-Deutsche  WafTen  and  Municionsfabriken  A.  G.,  Posen  Works 
emp-Dynamit  A.  G.,  (formerly  Alfred  Nobel  & Co.)i  Empeldc 
Works 

eom-H.  Huck  Merallwarenfabrik,  Numberg 

F 

fa-Mansfield  A.  G.,  Hctescedt,  Sudharz 

faa-Deucschc  Waffen  and  Miinitionsfabriken  A.  G.,  Karlsruhe 
fd-Stolbergcr  Mctallwcrkc  A.  G.,  (fonnerly  Asien,  Lynen  and 
Schleicher),  Stolberg 

fde-Dynamic  A.  G.,  (formerly  Alfred  Nobel  k Co.),  Forde  Works 
fva-Draht  and  Metallwarenfabrik  G.  m.  b.  H.,  SaUwcdcI 

G 

geb-j.  F.  Eisfeld  Pulvcr  and  Pyrotechnische  Fabrikcn  Gnnrers- 
berge 

H 

ha-Truenbritzen  Metallwarenfabrik,  G.  m.  b.  H.,  Werke  Sebal- 
dushof 

ham-Dynamic  A.  G.,  (formerly  Alfred  Nobel  & Co.),  Hamm 
Works 

has-Pulverfabrik  Hasloch,  Hasloch  am  Main 
hgs-W.  C.  Gustav  Burmeiscer  Pyrotechnische  Fabrik  and  Signal - 
miccelwerk,  Hamburg 
hrg-Polre,  Duderscadt  Works 


414 


Hatcher’s  NuTEBowi. 


jtb-S.  A.  Tauavo,  Geneva 


k-Luch  & Wagner,  Suhl 

kam-Hasag  Eisen  and  Mcialhverkc  G.  m.  b.  H.,  Skarzysko-Dami- 
enna  Works 

kfg  Sarajevo  Scare  Arsenal 
klh-I,,  Kiesscihach 

krl-Dynamit  A.  G.,  (formerly  Alfred  Nobel  & Co.).  Work  Kruni- 
niel 

kry-I/ignose  SprengseofF  Werke  G.  m.  h.  H.,  Werk  Knippamuhle 
kunAVerk  Kunigunde 

kye>Inrreprmderile  Metalucgie,  Puinitra  Voina  Socictatc  Anonima 
Romana,  Fabrica  de  Armament,  Brasov,  Roumania 
kyn-Ascra,  Fahrica  Romana  dc  Vagocne,  Motoane  Ammiiicnt  si 
Municiuni,  Brasov,  Roumania 

kyp-Runianlsch>Dcjcsche  Industrie  and  Handels  A.  G.,  Bucharest 

E 

!dc-Deucschc  Pvrotcchnische  Fabriken  G.  m.  b.  H.,  Clcebronn 
Idb-Deutschc  ^yrorcchnischc  Fabriken  G.  nt  h.  H.,  Malcho\^» 
Berlin 

Idn-Dcurschc  Pyrotechnischc  Fabriken  G.  m.  b.  H.,  Ncumarkt 
Ige-Kugclfabrik  Sclmltc  & Co..  Tcnre,  Rhineland 
IknvMunitionsfabriken,  (formerly  Sellier  and  Rellor).  Prague 

X 

nbc-Hasag,  Lisen  and  Metallwcrkc  G.  m.  b.  H.,  Werk  Apparaebau 
Tachenstocnau 

nfx-RWS  Miinitionsfabrik  G.  m.  b.  H.,  Warsaw-Praguc 

Q 

(]ve-Carl  Walther,  Zella-Mehlis,  Thuringia 

V 

Va-Kabel  and  Metallwerkc  Neumeyer  A.  G.,  Nlirnberg 

W 

wa-Hugo  Schneider  A.  G.,  Lampenfabrik  I-eipsig 
wb-Hugo  Schneider  A.  G,,  Kopenick  Works,  Berlin 
wc-Hugo  Schneider  A.  G.,  Meusewitz  Works 
wd-Hugo  Schneider  A.  G.,  Tancha  Works 
we-Hugo  Schneider  A.  G.,  I^ngcwciscn  Works 
wf-Hasag  Eisen  and  Metallwerkc  G.  ni.  b.  H.,  Kielce  Works 
wg-Hugo  Schneider  A.  G.,  Altenburg  Works 
wh-Hugo  Schneider  A.  G.,  Eisenach  Works 
wj-Hugo  Schneider  A.  G.,  Oberweissbach  Works 
wk-Huffo  Schneider  A.  G.,  Schiieben  Works 

Y 

v-jagdpatronen,  Zundhutchen  and  Metallwarenfabrik  A.  G.,  Nagy- 
teteny  Works,  Budapest 


4*5 


Random  Notes  on  Various  ScBjKcrrs 

Optical  Instrument  Makers'  Codes 

B 

beh-t‘msr  I.eitz  G.  m.  b.  H.,  Wetzlar 
bek-Hensoldt  VVcrk  fnr  Optic  and  Mcchanik,  Ilcrborn 
bIc-Zciss  MilitarabCfiilung,  Jena 
bmj-llcnsoldc  and  Sobne,  Mechanibche  Optische  Werk  A.  G., 
Wetzlar 

bpd-Opciiche  Anstalt  C P.  Goeiz,  Vienna 

byg-Joh,  Wyksen,  Optische  and  Feinmaschin,  Ka^owit^ 

C 

cag-bwarovski,  \\  Glasfabrik  und  Tyrulit,  VVaiten*;,  Tyrol 
ccx-Optische  and  Feinmechanische  Werke  Hugo  Meyer  and  Co., 
Gorliu 

Cro-R.  Fuess  Optische  Industrie,  Sceglitz,  Berlin 
cm-Hanseatische  Werkstatten  fur  Feinincchanik  and  Optik,  Freid- 
ricks  and  Co. 

cxn'Emil  Busch  A.  G.,  Optische  Industrie,  Rathenow 
czU'Emil  Busch  A.  G..  Optische  Industrie,  Rachenow 

D 

ddX'VoigtIander  and  Sohn  A.  G.,  Braunschweig 
dpw-Zeiss  Ikon,  Dresden;  also  Zeiss  Ikon.  Goerz werke,  Bcrlin-Zcch- 
Icndorf 

dpx-Zeiss  Ikon,  A.  G.,  Stuttgart 
dym-Runge  and  Kaulfuss,  iGthenow 
dzUOptische  Anstalt  Oigee,  Berlin 

E 

eaf-Mechanoptik  Gescllschaft  fur  Prazisions-technik,  Aude  and 
Reipe  Optische  Industrie,  Babelsbcrg 
emq-K^rl  Zeiss,  Jena  (on  some  range  finders,  etc.) 
eso-Optischc  Werke  G.  Rodenstock,  Moachen 
ciig-Optische  Prazisinns  Werke  G.  m.  b.  H.,  Warsaw 

F 

fco  Sendlinger  Optische  Glaswcrkc  G.  m.  b.  II.,  Zehlendorf.  Berlin 
fwr-Optischc  Anstalt  Saalfdd  G.  m.  b.  H.,  Saalfeld 
fxp-ll.  Kollmorgen  G.  m.  b.  H.,  Berlin 

G 

ghp-Ruf  and  Co.,  Kassel 

gug-Ungarischc  Optische  Werke  A.  G..  Budapest 
guj-Werner  D.  Kuehn  Optische  Industrie,  Stcglirz.  Berlin 

H 

hdv-Optische  Werk  Osterode  G.  m,  b.  H.,  Oscerodc,  Harz 
hkm-Carl  Braun  A.  G.,  Optische  Industrie,  Nil  mb  erg 

J 

jfp-Dr.  Carl  Leiss,  Optische  Mechaoische  Instrumente,  Steglitz, 
Berlin 


Hatcher’s  Noixbook 


416 

jnh-ilensoldc  Werke  fur  Optik  und  Mecliaiiik,  Herborn,  Dillkress 
jve-Opcisclies  Wcrk  Emsc  Ludwig,  Weixdorf 

K 

kjj-Sccn  on  many  binocuJars  but  not  tisud  in  code  book 
krg'Lniil  Busch  A.  G.,  Optische  Werke,  Budapest 
kwe-Gamma  Feinmechan  and  Optische  Werke,  Budapest 

L 

lae<Heinrich  Zeiss,  Gastingen  . 

Jmg-Carl  Zeiss,  Jena 

Jwg-Oprische  Wcrk  Osterodc  G.  in.  b.  H.,  P'reiheit  bei  Osccrode 
(Harz) 

Iww-Huct  & Co.,  Paris 

Iwx-O.  P.  L.  (Optikue  et  Pr^ision  de  Levallois),  Levallois,  Paris 
Jwy-Societe  Optique  et  Mechanique  de  Haute  Precision,  Paris 

P 

pvf-Opcische  Werk  C.  Reichert,  Vienna 

25.  Head  Stamps  on  U.  $•  Service  Cartridges 


ipiS  tracer 


D A 

Dominion  Arsenal 

D-il:t 

Dominion  Arsenal 

if, 

D I 

Defense  Industries,  Canada,  Ltd. 

DEN 

Denver  Ordnance  Plant 

F,  C 

E va  ns  vil  Ic -Ch  rvslcr 

AS 

ECS 

E V ans  vi  11  c • Ch  ry  sic  r-Sunbea  m 

•45 

E W 

EauClaire  Ordnance  Plant 

F A 

Frankford  Arsenal 

F M 

Fabrica  Nacional  de  Muntciones 

(Mexico).  Experimental.  N' 

G E 

General  Electric  Company 

K S 

Allegheny  Ordnance  Plant 

.50 

L C 

Lake  City  Ordnance  Plant 

1.  M 

Lowell  Ordnance  Plant 

.50 

M 

Milwaukee  Ordnance  Plant 

.50 

PC 

Kings  Mills  Ordnance  Plant 

P C C 

^pr 

Peters  Cartridge  Company 

Q A 

Dominion  Arsenal  (Quebec) 

R A 

Remington  Arms  Company 

T R 

Three  Rivers  (Quebec) 

r w 

Twin  Cities  Ordnance  Plant 

U,  U Y 

Utah  Ordnance  Plant 

V c 

Verdun,  Canada 

Non 

W,  W 18 

Western  Cartridge  Company 

w c w c c 

Western  Cartridge  Company 

W R A 

Winchester  Repeating  Arms  Company 

r 

otll)' 


26.  Army  Test  Procedure  and  'Weapons  Nomenclature 
So  that  the  reader  may’  better  understand  the  reason  for  our 
references  to  the  various  tests  held  at  Aberdeen,  Springfield  Armory, 


Random  Scrips  os  Various  Subject's 


4'7 


Fore  Bciming,  and  other  places,  it  might  l>e  well  at  this  point  to  sav 
a few  words  about  how  the  Army  goes  about  the  matter  of  obtain- 
ing a new  weapon. 

The  Ordnance  Department^  contrary  to  the  usual  impression,  does 
not  have  the  say  as  to  what  weapons  the  Army  uses.  Tlte  Ordnance 
Department  is  merely  a I'cchnical  Service  ihmugli  which  the  Using 
Service  orders  the  fighting  material  that  it  needs. 

All  inventions  muse  be  sent  first  to  the  National  Inventor’s  Council 
of  the  Department  of  Commerce,  Washington  25,  D.  C.  Only  those 
that  the  Council  decides  should  have  Army  Department  action  may  be 
considered  by  the  Army  Depanmenr.  These  arc  sent  to  the  proper 
agency  of  the  Army  Department  for  action  by  its  Technical  Com- 
mittee. 

Immediately  after  World  War  I,  the  Ordmnee  Cornniiuee  was 
formed  to  co-ordinate  and  control  the  work  to  be  done  by  the 
Ordnance  Department  for  all  of  the  Using  Services.  This  Committee, 
which  meets  fortnightly,  is  composed  of  representatives  of  the  Ground 
Forces,  the  Air  Force  and  the  Navy,  the  Marine  Corps,  and  the  Coast 
Guard,  together  with  members  from  the  Ordnance  Department  and 
from  the  other  Technical  Services  as  well 

The  general  function  of  the  committee  is  ^’to  consider  and  recom- 
mend technical  action  upon  all  macrers  afTccring  material  designed  for 
and  intended  to  be  issued  to  the  Armed  Forces,  coming  within  the 
jurisdiction  of  the  Ordnance  Department.'* 

Through  this  cominitiec  the  using  Arms  of  the  Service  express 
their  desires  and  needs  as  to  new  and  better  equipment;  have  a 
definite  voice  as  to  the  characteristics  and  functioning  of  contemplated 
or  proposed  material;  and  are  in  a position  to  accept  nr  reject  a newly 
developed  item  before  it  is  srandardi^ted  and  goes  mf(*  full  production. 

Frequently  the  Ordnance  Committee  Itas  given  the  Ordnance  De- 
partment authority  to  proceed  wkh  the  development  of  an  item  for 
which  no  present  requirement  but  which  seems  to  be  in  line 

svich  probable  future  progre:»s,  so  that  we  mav  keep  ahead  of  foreign 
developments. 

Occasionally  there  may  exist  a requirement  in  the  minds  of  the 
public  or  in  that  of  an  arm-chair  strategist  or  of  a newspaper  column- 
ist, when  the  using  ser\'ice  thinks  otherwise.  Usually  in  such  a situa- 
tion the  Ordnance  Department  comes  in  for  severe  casrigation  by  the 
press  for  supposed  backwardness.  For  example,  in  the  early  part  of 
World  War  II,  the  Ordnance  built  and  pcrtectcd  a heavy  tank,  and 
had  it  ready  for  production  in  case  a requirement  should  arise. 

However,  the  using  service  found  that  such  tanks  were  very  diffi- 
cult to  transport  over  the  great  distances  from  our  bases  to  the  points 
where  we  were  fighting.  Bridges  wouldn’t  carry  them;  especially 
the  then  existing  temporary  bridging  chat  had  already  been  procured 
in  quantity  by  the  Engineers.  It  was  decided  that  a larger  number  of 


Hatch  f.R’s  Notebook 


41S 

smaller  tanks  could,  on  account  of  their  much  greater  mobility,  be 
gotten  to  the  needed  points  so  much  more  quickly  that  they  would 
he  more  effective.  The  rank  sat  at  Aberdeen,  wirfi  the  designs  com- 
pleted, ready  to  he  placed  in  productinn  at  a moment’s  notice  if 
needed. 

In  the  meantime  the  Germans,  who  were  fichring  right  at  the 
doors  of  their  own  factories,  and  thus  did  not  have  the  transporta- 
tion dldiculties  that  faced  us  with  our  long  lines  of  communication, 
placed  a heavy  tank  into  operation.  Immediately  the  Ordnance  De- 
partment was  severely  taken  to  cask  by  the  press,  in  spice  of  the 
fact  our  heavy  tank  had  been  ready  for  production  months  before. 

Ac  the  lime  of  the  Scmi-automacic  Ride  Tests  in  1919,  the  Infantry, 
Cavalry,  Artillery,  etc.,  each  had  its  own  Chief  with  an  office  in 
Washington  and  a Staff  of  his  own,  and  a Service  School  and 
Service  Board. 

In  attempting  to  produce  or  procure  a design  fur  a semi-automaric 
rifle,  it  therefore  became  necessary  for  the  Ordnance  Department  to 
obtain,  through  the  Ordnance  Committee,  ri\c  requirements  of  each 
of  these  using  services  for  the  Semi-automatic  Rifle,  together  with  the 
military  characteristics  desired. 

The  next  step  was  to  test  at  Springfield  or  Aberdeen  each  design 
prepared  by  our  own  engineers  or  submitted  by  inventors  to  see 
chat  they  were  suitable  from  an  engineering  and  mechanical  view- 
point for  actual  field  test  by  the  services.  If  they  were,  the  next 
move  was  to  submit  samples  to  the  Using  Services,  who  then  made 
their  own  tests  to  see  if  the  gun  met  the  military  and  Tactical  re- 
qiiiremenn  desired  hy  them. 

After  the  mechanical  and  engineering  tests  by  the  Ordnance  De- 
partment, the  service  tests  were  made  at  the  Infantry  Board,  Fort 
Benning,  the  Cavalry  Board  at  Fort  Riley,  the  Artillery  Board  at 
Fort  Sill,  the  Engineering  Board  at  Fort  Bclvoir,  etc. 

This  clumsy,  expensive,  and  time  consuming  process  was  greatly 
streamlined  and  shortened  when  the  various  arms  were  integrated 
into  a Ground  Force  with  one  Commanding  General  and  Staff. 

When  the  Using  Services  had  determined  that  the  item  met  ail  re- 
quirements and  had  the  necessary  characteristics,  the  Ordnance  Com- 
mittee was  so  informed,  and  then  recommended  to  the  General  Staff 
chat  the  item  be  standardized. 

When  Standardization  w*as  accuallv  accomplished,  the  item  was 
given  an  M or  Model  designation,  as  for  example,  the  U.  S.  Rifle, 
Caliber  .30,  \ii.  Later  changes,  or  Alterations  are  given  an  A number 
following  the  M number,  as  for  example  the  U.  S.  Carbine,  Caliber 
.30,  M I A !• 

Items  wl^ich  have  not  been  standardized  have  T or  Test  numbers, 
followed  by  E or  Experimental  change  numbers,  as  for  example, 


4*9 


Random  Notes  on  Vakiovs  Subjects 

Rifle  T 13  E 4 would  mean  that  this  was  the  4th  experimental  vari- 
ation of  the  13  th  test  model. 

The  British  use  the  word  Mark  instead  of  Model;  thus,  Rifle,  caliber 
.303  Mark  1.  Minor  changes  that  we  call  alterations  and  give 
designations  they  identify  with  a called  “S^ari^  Thus  Rifle 

<]ah1)er  .303  Mark  II*,  called  “Mark  Two  Scar.'’ 

In  describing  Japanese  Ordnance,  the  U.  S.  Army  has  adopted  a 
standardized  system  of  writing  the  Japanese  .Model  Number  first, 
followed  by  the  year  of  the  Christian  Era  in  parenthesis,  followed 
by  the  bore  of  the  piece  in  millimeters,  then  the  name  of  the  item. 
Eor  example,  the  Model  92  (1932)  6.5  mm  Heavy  Machine  Gun. 

Before  the  death  of  the  Emperor  Mciji  in  1912,  the  Japanese  ord- 
nance was  marked  in  accordance  with  the  year  of  his  reign,  which 
began  in  18^7.  Thus  the  Model  38  (1905)  6.5  inni  rifle  was  adopted  in 
rhe  38th  year  since  1867,  which  was  1905. 

Likewise,  during  the  reign  of  the  Emperor  Taisho,  which  began 
in  1913  and  ended  in  i925»  weapons  were  marked  by  the  year  of 
their  adoption  reckoned  in  the  Taisho  era  beginning  with  1912.  Thus 
the  model  n (192:)  6.5  mm  light  machine  gun  was  adopted  in 
the  nth  year  of  the  Taisho  Era,  and  the  Model  14  (1925)  8 mm 
Nambu  Pistol  w'as  adopted  in  the  last  year  of  the  Taisho  Era. 

Since  the  death  of  the  Emperor  Taisho,  most  Japanese  weapons  have 
been  marked  with  the  last  two  digits  of  the  year  since  the  founding  of 
the  Japanese  Empire,  which  it  is  supposed  took  place  j66o  years  B.C. 
Thus  when  the  Japanese  heavy  machine  gun  was  adopted  in  1932*  that 
was  the  year  2592  of  rhe  Empire. 

The  Japanese  year  2600,  which  in  our  system  is  1940,  is  referred 
to  by  the  last  digit  only,  and  becomes  the  year  0,  hence  the  name 
Zero  for  the  famous  Japanese  fighter  plane  adopted  in  that  year. 
Likewise  1941  i$  their  year  2601,  and  items  adopted  then  are  Model 
I (1941);  etc. 

Many  Japanese  weapons  are  named  with  Shtywa  numbers,  gmng 
the  year  and  month  of  manufacture,  starting  with  the  accession  of 
the  present  Emperor,  Hirohito,  who  began  lixs  rule  on  the  2dth  of 
December  1925.  The  era  of  his  reign  has  been  given  the  name  Shon^dy 
and  accordingly  the  year  of  15^  would  be  Sho'wa  23.  Thus  a Nambu 
Pi.scol  marked  14.5  was  made  in  May  1935* 

27.  Methods  of  Measuring  Chamber  and  Bore 

It  frequently  becomes  necessary  to  determine  the  shape  and  di- 
mensions of  the  chamber  of  a gun,  particularly  when  the  weapon  is 
of  an  unknown  caliber,  and  it  is  desired  to  identify  the  cartridge  for 
which  it  is  chambered. 

The  common  way  to  do  this  is  by  taking  a cast  of  the  chamber  in 
melted  sulphur,  and  then  measuring  this  cast  When  it  has  cooled  and 
hardened. 


420 


Hatcher’s  Notebook 


consisting  of: 

Sulphur  2 ounces 

Powdered  Lampblack  5 grains 

Spirits  of  Camphor j drops 


I'he  chamber  and  about  1 iiK*h  of  the  bore  should  be  cleaned 
thoroughly  and  then  be  covered  with  a very  light  film  of  thin  dean 
oil.  Then  the  bore  just  ahead  of  the  chamber  should  be  stopped  with 
a cork  with  a wire  through  it  of  the  right  length  to  project  up 
iliryugh  the  chamber  when  the  cork  is  in  place.  This  wire  is  to  act 
as  a handle  for  the  sulphur  cast,  which  is  quite  brittle. 

The  sulphur  mixture  is  then  heated  slowly,  stirring  it  all  the  while, 
until  it  arrives  ac  a thin  pouring  consistency.  It  is  then  poured  into 
the  chamber  quickly,  and  allowed  to  cool  before  it  is  removed  by 
shoving  it  out  carefully  with  a cleaning  rod.  It  must  be  handled 
carefully,  as  it  will  be  quite  brittle. 

To  obtain  the  dimensions  of  the  chamber  as  well  as  its  shape,  the 
cast  can  then  he  nicasvircd  with  a micrometer.  There  is  some  shrink* 
age  to  this  mixture,  but  not  very  much  as  will  be  seen  from  the 
note  whidi  follows  giving  the  results  of  a test  of  this  point  made 
at  Fraiikford  Arsenal. 


There  is  another  method  of  making  chamber  ur  bore  casts  which 
avoids  the  danger  of  breakage  which  makes  the  sulphur  cast  some- 
thing of  a nuisance.  This  is  to  make  them  of  a low  melting  metal 
alloy  known  as  Woods  metal,  which  is  sold  for  this  purpose  by  some 
dealers  in  gunsmiths’  supplies.  It  is  also  available  from  the  Cerro 
de  Pisco  Copper  Co.,  and  their  distributors  under  the  name  of 
Cerrobend,  for  the  purpose  of  filling  thin  walled  pipes  while  bending 
them  to  keep  the  walls  from  collapsing. 

This  metal  melts  at  160  degrees  F,  which  is  less  than  the  boiling 
point  of  water.  It  has  the  desirable  characteristic  of  expanding  slightly 
while  cooling,  which  means  that  it  forces  itself  tightly  into  all  re- 
cesses,  rifling  grooves,  etc.,  and  does  not  shrink  while  cooling  as 
sulphur  docs.  Vhi$  non-shrinking  quality  is  due  to  the  bisniuni  it 
contains. 


Different  compositions  of  this  metal  melt  at  different  temperatures. 
Woods  Metal,  melting  at  i6o  degrees  F has  the  following  composi- 
tion: 


Bismuth  384%  Lead  30.8%  Cadmium  154%  Tin  154% 


A brass  casting  was  bored  to  fit  a standard  plug  gage  13/16  inch 
(.8125  inch)  in  diameter.  Four  sulphur  casts  were  made  in  this  hole, 
using  the  standard  Frankford  Arsenal  sulphur,  lampblack  and  cam- 
phor mixture  given  above.  The  casts  were  then  held  in  a fixture  so 
arranged  as  to  allow  precise  measuremems  to  be  made  without  mov- 


Raxdom  Notes  ox  Various  Slbjecis  42 1 


ing  the  cast.  Measurements  were  made  at  intervals  up  to  72  hours 
without  handling  or  moving  the  casts.  Results  were  the  same  for  all 
four  samples,  and  were  as  follows: 

Time  after 

pouring  H Hr.  1 Hr.  2 Hrs.  4 Hrs.  6 Hrs.  24  Hrs.  48  Hrs.  72  Hrs. 
Size  .8125  .8115  .8105  .8102  £ioi  .6095  .8085  .8085 

Shrinkage  0 .0010  m>io  ^>02  5 .002$  .0030  .0040  .0040 


The  test  was  repeated  on  three  samples,  which  immediately  after 
removing  from  the  hole  were  laid  on  a case  iron  flxuue.  Thas  the 
initial  cooling  was  at  a faster  rate  that  for  the  first  four  samples. 
These  three  samples  all  shrank  slightly  more  chan  the  others,  prob- 
ably due  to  the  sudden  change  of  temperature  as  the  cast  was  placed 
on  the  cast  iron  fixture.  Results  were  identical  for  these  samples,  and 
were: 


Tinic  after 

pouring 

-Si/e 

Shrinkage 


Hr.  I Hr.  2 Hrs.  4 Hrs.  6 Hrs.  24  Hrs.  48  Hrs.  72  Hrs. 
.He  (3  .8it>5  J^ior  .8101  .8101  .Hoyo  .HiiHo  .HoHo 

«oo(o  4>020  .0023  UM24  /x>24  <00)5  .004$  .0045 


28i  Reference  List  of  Numbers  Marking  Changes  in  Gnn  Design 

or  Manufactore 

rifles  of  Springfield  Armory  rnakc.  Rifles  having  serial  num- 
bers below  800,000  had  receivers  and  bolts  made  of  case  hardened 
steel.  While  they  were  very  strong  to  a steady  pressure,  they  had  low 
resistance  to  shock,  and  son>e  of  them  have  failed  in  service. 

M rifles  made  at  Rock  Island.  285,507.  Rifles  having  serial 
numbers  below  this  figure  had  the  same  case  hardened  receivers  and 
bolts  as  the  early  Springfields.  Those  having  serial  mimbei's  between 
285,507  and  319,921  have  carbon  steel  receivers  and  holts  with  an 
improved  heat  treatment.  Those  with  numbers  above  319,921  niav  be 
either  nickel  steel  or  carbon  steel  with  the  improved  treatment. 

M 1^0^  rifles  made  at  Springfield  Armory.  800,000  to  1,275,767. 
Rifles  having  serial  numbers  from  800,000  to  1,275,767  have  a double 
heat  treatment  which  gives  them  a hard  skin  to  withstand  wear, 
together  with  a relatively  soft  and  highly  tenacious  core,  which  gives 
them  tremendous  strength  and  resistance  to  shock.  These  are  the 
strongest  and  best  receivers  and  bolts. 

M and  At  rifles  made  at  Springfield  Armory.  Rifles  hear- 
ing serial  numbers  from  1,275,767  to  1,532,878  have  nickel  steel  re- 
ceivers and  bolts.  These  have  a somewhat  “stickv”  action,  as  the 
surface  skin  is  not  as  hard  as  that  of  the  double  heat  treated  receivers 
and  bolts.  The  strength  of  these  nickel  steel  receivers  and  bolts,  while 
less  than  that  of  those  having  the  double  heat  treatment,  is  entirely 
satisfactory.  I do  not  know  of  any  report  of  one  having  been  blown 
up  in  service,  though  in  tests,  a “destruction  load’'  which  will  burst 
a nickel  steel  receiver  will  leave  a double  heat  treated  one  unmoved. 


Hatcher’s  Notebook 


42  2 

M ipoj  and  M A $ 07id  A 4 rifles.  Rifles  bearing  serial  numbers 
from  3,ooo»ooo  to  5,784,000  inclusive  were  made  during  World  War  II 
by  the  Remington  Arms  Co.,  or  by  the  L.  C.  Smith-Corona  Type- 
writer Co.  These  have  chrome  nickel  steel  receivers  and  bolts. 

Colt  Woodsmm  pisiols.  Pistok  below  number  85,790  originally  had 
mainspring  housings  intended  for  low  speed  aiiiiiiunition.  Those  above 
this  number  have  specially  heat  treated  mainspring  housings  intended 
CO  withstand  the  higher  shock  of  the  stronger  ammunition.  New 
housings  may  be  Acted  to  old  pistols.  The  type  of  housing  may  be 
determined  by  the  type  of  cross  milling  on  the  thumb  spot  on  the  rear 
of  the  housing.  The  old  type  is  checkered,  while  the  new  type  is  milled 
straight  across  with  parallel  lines. 

Colt  automatic  ptsioh  .5^0  caliber.  Pistols  below  number  98,894  do 
not  have  the  magazine  safety.  Tliose  of  later  serial  numbers  do.  That 
is,  they  cannot  be  fired  unless  the  magazine  is  in  place. 

Colt  ,2j  Caliber  automatic  pistols.  Pistols  with  serial  numbers  less 
than  141,000  do  noc  have  the  magazine  safety. 

Colt  .32  caliber  automatic  pistols.  Pistols  with  serial  numbers  below 
468,097  do  not  have  the  magazine  safety. 

Colt  Single  Action  Army  Revolvers.  Bevolvci*s  up  to  number 
i6o,uoo  sliuuld  be  used  with  black  powder  only.  After  this  number, 
have  heat  treated  cylinders  designed  co  use  smokeless  loads. 

&mith  ^ Wesson  .5^  M.  & P,  The  weapon  with  number  241,706 
was  the  first  co  have  the  Paceoc  Safety  Hammer  Block. 

Colt  Woodsman  pistols  made  before  1947  do  noc  have  the  maga- 
zine safety. 

29.  Oveiioadi  in  Revolvers 

In  1914  a commission  was  sent  to  Cuba  by  duPont  co  investigate 
trouble  reported  from  bursting  of  .45  caliber  revolvers. 

It  was  round  chat  two  bullets  loaded  in  the  same  case  would  burst 
the  revolver,  also  it  was  found  that  a double  charge  of  powder  would 
burst  the  revolver.  The  standard  charge  was  5.91  grains  of  Bullseyc 
No.  2,  and  the  coininission  experiiiiented  with  overloads  of  j,  2,  3, 
4,  5,  and  6 grains  in  addition  to  the  regular  charge. 

With  5 grt.  overload,  total  10.91  ’ revolver  burst  on  the  3rd  shot 

With  5 grs.  overload,  total  10.91  * revolver  bum  on  the  4th  shut 

With  6 grs.  overload,  total  11.91  grs.  1 revolver  burst  on  the  4th  shot 

With  6 grs.  overload,  total  11.91  gm  i revolver  burst  on  the  3rd  shot 

30.  Target  McasuFcmcnts 

Mean  Radius  is  the  averse  distance  of  all  the  shots  from  the  center 
of  the  group.  It  is  usually  about  one  third  the  group  diameter. 

To  obtain  the  mean  radius  of  a shot  group,  measure  the  heights  of 
all  shots  above  an  arbitrarily  chosen  horizontal  line.  Average  these 
measurements.  The  result  is  the  height  of  the  center  of  the  group 
above  the  chosen  line.  Then  in  the  same  way  get  the  horizontal  dis- 


Random  Notfs  ok  Varioiji%  Subjects  423 

tancc  of  the  center  from  some  vertical  line,  such  as  for  instance,  the 
left  edge  of  the  target.  These  two  measurements  will  locate  the 
group  center 

Now  measure  the  disiancc  of  each  shot  froni  this  center.  The 
average  of  these  measurement  is  the  Mean  Radius. 

Group  Diameter.  The  distance  between  the  centers  of  the  two 
most  widely  separated  shots  in  the  group. 

Figure  of  Merit.  A method  adopted  by  the  Ordnance  Department 
in  19:3  for  evaluating  very  small  groups,  [t  is  obtained  as  follows: 
Draw  a vertical  line  through  the  lowest  shot  in  the  group,  also 
through  the  shot  furthest  to  the  left.  Add  the  distance  from  the 
bottom  line  to  the  highest  shot  to  that  from  the  vertical  line  to  the 
shot  furthest  to  the  riglu.  Divide  by  two. 

Extreme  Vertical.  For  the  1929  Ammunition  Tests,  the  Ammuni- 
tion Board  adopted  the  Extreme  V'crtlcal,  or  the  vertical  distance 
between  the  highest  and  the  lowest  shut  as  the  measure  of  ammuni- 
tion performance. 

31.  Weights  of  Weapons 

The  w'eight  of  a rifle  or  other  siitall  arm  is  an  important  part  of 
the  description,  but  it  Is  not  a flxed  and  unvarying  quantity,  as  the 
wood  of  tne  stock  varies  greatly  in  density  from  one  gun  to  the  next, 
so  chat  the  quoted  weight  of  a rifle  should  be  considered  as  an 
average. 

'rhe  weight  of  the  regular  issue  stocks  for  the  Springfield  M 1903 
nr  the  Garand  Mr  may  vary  from  one  to  the  next  as  much  as  a pound 
and  a half,  though  the  usual  variation  is  much  less. 

My  own  three  Springfield, s as  issued,  weigh  as  follows: 

Regular  M 1905,  with  straight  stock  8 lbs.  4 02. 

1903  A I,  with  pistol  grip  stock,  9 lbs.  d 02. 

1903  A 3,  made  by  Smith-Corona  8 lbs.  6 oz. 

32.  Weights  and  Measures,  English  and  Metric 

While  the  English  speaking  countries  use  the  foot,  pound  and 
gallon  as  fundamental  units  of  length,  weight,  and  measure;  most  other 
countries  use  a decimal  system  based  on  the  meter,  which  was  in- 
tended to  be  a millionth  of  the  quarter  circumference  of  the  Earth, 
but  actually  after  it  was  established  as  a standard,  was  found  to  have 
missed  this  intended  length  by  a smalt  percentage. 

The  Metric  System,  besides  being  a decimal  system,  has  all  the 
various  series  such  as  length,  weight,  etc.,  connected  together  by 
the  fact  that  the  unit  of  weight  is  the  weight  of  a cube  of  water  at 
maximum  density  one  hundredth  of  a meter  on  a side,  called  the 
gram,  and  the  unit  of  volume  is  the  volume  of  a cube  one  tenth  of 
a meter  on  a side,  called  the  liter. 

t^Nrrs  OF  LENGTH 

Tn  the  English  System,  the  unit  of  length  is  the  foot,  which  is  re- 


Hatch  KB  *s  NortBOOK 


4H 

laced  to  the  other  units  of  length  in  the  same  system  as  shown  below: 
J2  inches  = i foot 

inches  — 3 feet  = 1 yard 

5280  feet  = 1760  yards  = 1 mile 
In  the  Metric  Systejn  the  fundanicntal  unit  of  length  is  the  meter, 
which  is  39.37  inches  or  3.2808  feet  or  1.0936  yards.  It  will  be  seen 
that  it  is  roughly  3 feet,  3 inches,  and  3 tenths,  which  is  a good  way 
to  remember  it,  though  actually  four  tenths  is  closer.  It  is  also  about 
a yard  and  a tenth,  which  is  handy  to  remember  when  on  the  range. 

10  millimeters  = i centimeter 
joo  millimeters  = lo  centimeters  — i decimeter 

1000  millimeters  = >00  centimeters  = 10  decimeters  » 1 meter 

iooo  meters  — 1 kilometer 
VNITS  OF  WRKiHT 

in  the  British  System  the  pound  is  the  basic  unit  of  weight,  but 
there  are  three  kinds  of  pnimd.  For  weighing  ordinary  merchandise, 
tlie  avoirdupois  pound,  01  7000  grains  of  16  ounces  is  used.  The  troy 
pound  is  used  for  weighing  gold  and  silver,  and  the  apothecaries 
pound  for  weighing  drugs,  etc.  Both  these  have  5,760  grains  and  12 
ounces,  but  the  lesser  suodivisions  differ. 

It  is  indeed  fortunate  that  the  grain  is  the  same  in  all  three  of  the 
pounds  used  in  the  British  System. 

For  large  weights,  the  ton  is  used,  but  there  are  two  kinds  of  ton; 
the  long  or  gross  ton  of  2240  lbs.,  which  is  the  kind  used  in  ballistics, 
and  the  short  or  net  ton,  of  2000  lbs. 

Avoirdupois  Weight 
24.34375  » I dram 

[6  drams  or  437*5  grains  = 1 ounce 
16  ounces  or  7000  grains  ^ 1 lb. 

14  tbs.  = I stone 

2 stone  or  28  lbs.  — 1 quarter 

4 quarters  or  112  lbs.  = 1 hundredweight  (ewt) 

20  cwc.  or  2240  lbs.  = I ton  (loi^  or  groj.s  ton) 

2000  lbs.  = I short  con  (Net  ton) 

Note:  The  stone  and  quarter  are  commonly  used  in  Great  Britain 
but  not  in  the  U.  S. 

Troy  Weight 

24  grains  = 1 pennyweight  (dwt.) 

20  pennyweight  or  480  gr.  = 1 ounce 
rz  ounces  or  5760  gr.  ^ 1 pound 

Apothecaries  Weight 
20  grains  =*  i scruple  (®) 

3 scruples,  or  60  gr.  = i drachm  (3) 

8 drachms  or  480  gr.  = r ounce  (5) 

12  ounces  or  5.760  gr.  — i pound  (lb.) 


Random  Notes  ok  Various  Subjecis 


425 


In  the  Metric  System  the  fuadaniental  unit  of  weight  is  the  gram, 
which  was  intended  to  be  exactly,  and  very  nearly  is,  die  weight  in 
vacuum  of  a cubic  ceniiineter  of  pure  water  at  maximum  density. 
It  is  equal  to  15  43  a grains.  The  other  units  are  shown  below^: 

1000  milligrams  = 1 gram 

1000  grams  = j Icilogram 

1000  kilograms  ^ i tonne  or  metric  ton 

I'hc  pressure  of  the  atmosphere,  or  14.7  lbs.  per  sq.  inch  is  often 
used  as  a measure  of  powder  pressures,  and  is  abbreviated  as  atm. 
In  the  Metric  System,  the  unit  of  pressure,  i kilogram  per  square 
ccticimeter,  or  14.223  lbs.  per  square  inch  is  sometimes  called  a 
Technical  Atmosphere,  abbreviated  as  at. 

Comparative  Tables  of  Weights 


1 grain  = ^4.9  mlUigiams  = 

45649  gram 

I dram  = 1770  mill^rams  = 

1.77  gram 

I ounce  — 28350  mdl^rams  = 

28.35  gram 

t pound  = = 

453.59  gram= 

453 

1 long  ton  = 

uu6. 

kg—  1.016  tonne. 

1 short  ton  — 

kg  5=  907  tonne. 

r milligram  ~ .0154  grain 

1 gram  = 15432  grato=  .0353  ox. 

r kilogram  = 15432  grain  = 35.3 

oz.  = 2.2046  lb. 

1 rnnne 

= 2204.6 

lb. 

= .9B42  Jong  con 

j tonne 

= 2204.6 

lb. 

= 1.023  short  ton 

I lb  per.  sq.  inch  = .0703  kg.  per  sq.  cm. 

t ton  per  sq.  inch=  15749  kg.  per  sq.  cm. 

I foot  pound  = .1582  kg.  meter 

I foot  ton  = 309.7  kg.  meter 

I atmosphere  (147  lbs.  per  sq.  m.) 
i kg.  per  aq.  cm.  = 14*253  lu 
i kg.  meter  = 

I merer  tonne  = 


per  sq. 
7.234  ft.  lbs. 
3.229  n>i^s. 


= .3097  meter  ton. 

= 1.033  technical  atmosphere 
in.  s tons  per  sq.  In.  = 967  atm. 


CONVERSION  F.ACTORS 


To  convert 

Grains 

Grains 

Ounces 

Pounds 

l.ong  Tons 

Short  Tons 

Milligrams 

Grams 

Kilc^rams 

Tonnes 

Tonnes 

Ft.  per  sec. 

Foot  pounds 


to  MUigrains 
CO  Grams 
to  Grains 
to  Kilograms 
to  Kilograms 
to  Kilograms 
to  Grains 
to  Grains 
to  pounds 


multiply  by 
multiply  by 
multipty  by 
nnltiply  by 

multiply  bv  1014^ 
malt^y  by  907 


multiply  by 
mnlti|3ly  by 
multiply  by 
multiply  by 
multiply  by 


649  or  divide  hy  >0154 
.0649  or  divide  by  15.4^ 
28.35  divide  by  *0353 
453  or  divide  by  2.205 
or  divide  by  .000984 

or  divide  by  .001023 


to  Long  Tons 
to  Short  Tons 

CO  Meters  per  sec.  mnlriply  by 
to  Kilogram  Meters  multiply  by 
Lbs.  per  sq.  in.  to  Kgs.  per  sq.  cm.  multipfy  by 
Meters  per  sec.  to  Feet  per  sec.  mnldply  by 
Kilogram  Meiers  to  Foot  pounds  nraltipty  by 
Kgs.  per  sq.  cm.  to  Lbs.  per  sq.  in.  mult^Iy  by 


451 54  or  divide  by  64.9 
15432  or  divide  by  .0649 

2.205  divide  by  455 

984201  divide  by  1016 
1013  or  divide  by  .907 

.304801  divide  by  3.28 
.1382  or  divide  by  7.234 
45703  or  divide  by  14.223 
3.28  or  divide  by  -3048 

7.234  or  divide  by  .1382 

14.223  or  divide  by  .0703 


Ha'ichkr’s  Notebook 


1 inch 
i foot 


I KiUc 


— J>254  m.  “ 2.54  cm.  = 254  mm. 
= .304S  m.  ^ J048  cm.  “ 304«^  mm. 
4^144  m.  — 9144  cm. 

= iA»95  km.  = 1^09.3  m. 


r s(|.  In.  — ~ 645  sq.  cm.  645.2  &q.  mm. 

1 sq.  ft.  = *^^9  sq.  m.  = 929  sq.  cm. 

I cu.  In.  = 16.387  c.  c. 


I mm.  — i ‘^3957 

I cm.  — .3937  in.  = u>}28  ft. 

I m.  — 39.37  in.  = 3.2808  ft.  = 1.0936  yds. 

t km.  = 3280.S  fc.  = >o93jS  yds.—  .6214  )nt. 

I sq.  cm.  ^ «*557i9  scj.  in. 
t sq,  m.  — 10.765  sq.  fc 

I c.  c.  ' = .06(024  cu.  in. 


To  conver- 

Inches  to  Millimeters  Multiply  by  254  or  divide  by  *03937 

Inches  to  Centimeters  Multiply  by  2.54  or  divide  by  .3937 

Feet  to  Centimeters  Multiply  by  3048  or  divide  by  .0328 

Feet  to  .Meters  Multiply  by  >3048  or  divide  by  3.2808 

Yards  to  .Meters  Multiply  by  .9144  or  divide  tiy  1.0936 

Miles  to  Kilometers  Multiply  by  t.609  or  divide  by  .6214 

Sq.  Ins.  to  Sq.  Cms.  Multiply  by  645  or  divide  by  .155719 

Cu.  Ins.  to  Cubic  Cms.  Multiply  by  16.387  or  divide  by  .061024 

To  convert  millirticters,  ccntin>ctcr$,  etc.,  to  inches  etc.,  reverse  the  above 
ubie,  rmiltiplying  where  division  is  indicated,  and  dividing  where  multiplica- 
tion is  indicated.  For  example,  to  convert  Millimeccrs  to  Inches,  Divide  by  254 
or  imiltiply  by  ^3937. 

In  many  cases  multiplication  or  division  may  be  avoided  by  reference  to  the 
following  tables: 


LCNCTHS  'MrLLIMBTTHS  TO  MXIMALS  Of  AS  INCH 

From  t to  too  Units 


Millimeters 

1 

0 

1 

1 

1 

3 

4 

S 

6 

7 

8 

1 

9 

0 

0 

•03937; 

•07874 

.1(8(1 

•*5748 

.19685 

.23622 

•27559 

BBiB 

•5545* 

TO 

•39370 

•43307 

47^44 

.51181 

.55118 

•59*>55 

.629921 

.66929 

.74803 

20 

,78740 

.82677 

.866x4 

.90551 

•94488 

4*8425 

1.02362I 

I/>6299 

1.10236 

1.14173 

50 

i.iSno 

(.22047 

1.25984 

1. 19921 

1.33858 

‘•37795 

141732 

1.49606 

*-53545 

40 

1.57480 

(.6(417 

T*^5354 

1.69291 

1.73228 

1.77165 

7.8x102 

1.85039 

1.88976 

1,929(3 

50 

1,96850 

1.00787 

2,04724 

2.08661 

2.12598 

2.16555 

200472 

2.24409 

2,28346 

2.32283 

60 

2,36220  240157 

244094 

24^31 

2.57982 

2.51968 

i.5^fl42 

2.63779 

2.67716 

2.71655 

70 

27559® 

1^795*7 

2.83464 

2.87401 

2.91338 

2-95275 

2W‘2 

3.03x49 

3,07086 

3,21023 

80 

3.14960 

3.18897 

3^6^! 

3.30708 

3 34^5 

3-38582 

i3-425*9 

3.46456 

3‘5®393 

90 

,3*54310 

1.58  4«7 

3.62204 

3.66141 

13.7007S 

3-740*5 

3‘7795‘ 

.3.8(889 

3.85626 

3.89763 

Random  Notfs  on  Various  Subjects 


427 


:XSGTHS^HVNUREOTHS  OF  AN  INCH  TO  MU.LIMETCRS 

From  I rn  IDO  Hundredtli5 


Him- 
Jredths 
of  an 
Inch 

0 

1 

1 

3 

4 

S 

6 

7 

8 ; 

1 

9 

1 

0 

^1 

*54 

.508 

.762 

! a>i6 

1.778 

2.032 

2.286 

CO 

*•54^ 

*•794 

3-048 

3.302 

4-M8, 

4-57* 

4.826 

20 

5a>Bo 

5.58* 

5.842 

6ag^\ 

64h 

6.8$8 

7.112 

7*566 

7.620 

7.874 

8.128 

8.3S2 

8636I 

8.890I 

9.(44 

9.598 

9.652 

9*906 

40 

jo.t6o 

(O.414 

(0.668 

10^922 

ti.176 

11430 

11.684 

11.958 

12.192 

>2446 

50 

12.700 

12.954 

13.208 

13462 

13.716 

*t«970| 

14.224 

14-478 

«4-7I* 

14^6 

60 

15.240 

*5494 

(5.748 

|6aK>2 

16.156 

i6.5fc^ 

16.764 

>7.018 

17.272 

17.526 

70 

17.780 

18.034 

18.288 

18.542 

18.796 

i9/»50 

19.304 

19.558 

19.8(2 

20066 

80 

20.320 

20.574 

20.82S 

2IX>82 

21.336 

**•844 

22.098 

22.352 

22.606 

90 

22.86o 

23.114 

1 23.368!  23.622 

23B76 

1 24-*  JO 

24.384 

24-63» 

24JI92 

15.146 

UQUID  MEASURE 

The  English  Imperial  Gallon  is  the  volume  of  ten  pounds  of  dis- 
cillcd  wafer  at  degrees  F.  It  contains  277.17  cubic  inches  or  4.543d 
liters,  and  is  very  nearly  j.i  U.  S.  Gallons. 

rhe  U.  S.  Gallon  contains  231  cubic  inches,  or  3.7853  liten.  It  is 
almost  exactly  c<jual  to  the  cemtents  of  a cylinder  seven  inches  in 
diameter  and  six  mches  high. 

The  Liter,  which  is  the  metric  unit  of  volume,  is  1000  cubic  centi- 
meters. [t  is  equal  to  61.024  cubic  inches. 

1 gallon  s 4 quarts  « 8 pints 

r quart  = 2 pints 
1 cubic  foot  = 7.48  U.  S.  Gallons 

I liter  = 2.1134  U.  S.  pints  = 1.0567  quarts  = .26417  U.  S. 

r U.  S.  gallon  = 3 785 3 Liters  Gallons 

I U.  S.  quart  = *9463  IJter 
I U.  S.  pint  .4731  Liter 

To  convert: 

Q.  S.  quarts  to  Liters  multiply  by  .9463  or  divide  by  1.0567 

U.  S.  gallons  to  Liters  multiply  by  3.7853  or  divide  by  .26417 

Uters  CO  U.S.  quarts  multiply  by  1.0567  or  divide  by  .9436 

Liters  to  U.S.  gallons  multiply  by  .26417  or  divide  by  3.7853 


428 


Hatch  lk"s  Notebook 

33.  Amencaa  and  Foreign  Caliber  Equivalents 

The  caliber  of  a gun  is  supposed  to  be  the  diameter  of  the  bore 
of  the  ^fi  in  hundredths  of  an  inch  or  in  miiimeters.  The  diameter 
of  tlic  bullet  is  usually  some  .008  inch  larger,  to  fill  the  grooves  of 
the  rifling.  However,  the  S.  & W.  .357  Magnum  is  named  from  the 
diameter  of  the  bullet,  not  the  bore,  co  distinguish  it  from  the  other 
bullets  of  the  same  diameter,  called  .38  caliber. 

There  arc  a number  of  other  anomalies  in  the  caliber  designations 
of  guns  and  cartridges.  For  example,  the  .303  Savage  and  the  .32-20 
are  really  .30  caliber  guns  and  the  .32  pistols  and  revolvers  arc  really 
.304  to  .305.  .38  Pistols  and  revolvers  are  jusi  under  .35  caliber, 
except  for  the  .38-40,  which  is  nearly  40  caliber,  and  is  just  the  same 
size  as  the  41  Colt. 

To  add  considerably  to  ihe  confusion,  the  different  makers  vary 
considerably  from  one  to  the  other,  in  spite  of  the  fact  that  they 
have  an  organization  which  is  supposed  to  standardize  these  dimen- 
sions. 

The  table  which  follows  gives  the  American  caliber  name,  the 
representative  average  bore  aiaineter  both  in  inches  and  in  milli- 
meters, and  the  caliber  name  in  the  Metric  system,  when  such  a 
name  is  commonly  used,  for  a number  of  popular  weapons  and  their 
cartridges.  Owii^  to  the  variation  between  the  various  makers,  as 
well  as  the  wide  tolerances  used  by  sonic  of  them,  weapons  will  often 
be  seen  which  may  differ  somewhat  from  the>se  exact  figures. 


Random  Notes  on  Various  Subjects 


429 


American  Caliber 
Name 

Average 

Bore 

Diameter, 

Inches 

Same  Bore 
Diameter  in 
Millimecers 
Caliber 

Name  in 
Millimeters 

.22  Rim  Fire 

.212^.218 

5-38-5-JJ 

5.6  mm 

6 mm  U.S.N. 

.236 

6x> 

6 mm 

.25  A.CJ^. 

•244 

d.20 

d.35  mm  Pistol 

.150/ 3000 

.250 

^•35 

.25  Remington 

.250 

d.35 

6.5  mm  MannJicher 

.156 

6.5 

rt.5  mm  Alannlicher 

.270  Winchester 

.170 

6S6 

7 mm 

.276 

7^ 

7 mm  Mauser 

•30-30;  .30  W.CJ*.;  30  Rem.  .300 

7.62 

.jo-UjS.  Army  (•30-40  Krag)  .300 

.30-ort  (.30  U.  S.  Gov’t) 

.300 

7j5t 

.303  Savage 

.300 

74i 

.32-20  (.32  W,CF.) 

.300 

?j6t 

7163  mm  Mauser  Pistol 

.3005 

7^3  mm  Mauser  Pistol 

7.65  mm  Luger 

.3001 

74$ 

7.65  mm  Luger 

303  British 

.303 

7‘7 

7.7  mm 

32  A.C.P. 

}OiS 

7*75 

7.6s  mm  Pistol 

32  Cole  and  S.  & W. 

•J045 

7«73 

i mm  Mauser 

.312 

7-9* 

7.92  or  79  mm 

32  Win.  Spl.;  .32  Rem. 

•J*5 

38  Colt  and  S.  & W. 

8.8 

380  A.C.P. 

•1475 

8.83 

9 mm  Short 

38  A.C.P, 

•5475 

8.83 

9 mm  Luger 

•5475 

8^3* 

9 mm  Parabellum 

38  S.  & W.  Spl. 

•54^5 

8.85 

357  Magnum 

•5475 

8.85 

38-40  <.38  W.C.F.) 

•ms 

1O402 

4{  Colt 

•ms 

I04»2 

44  S.  & \V.  Spl. 

4185 

ioj6i 

A.CP. 

443 

11.25 

U.25  mm  Pistol 

4J5  Eley 

•444 

11.37 

455  Webley  k Scott 

Self-loading 

•4505 

”•44 

^ 

• Most  of  the  Lagers  thst  I have  owoed  hive  been  marked  on  the  bottom  of 
the  barrel  to  indicate  the  exact  bore  size  of  diac  parti  cuitr  barrel.  1 haTC  owned 
Lugers  marked  8.c,  8.2.  8.3,  and  8.4,  indicating  a range  of  bore  sizes  from 
.34^8  inch  to  .3480  inch. 


430 


$ 


Haicher's  Noterook 


34.  Value  of — 5“  tor  Temperature  and  Prewurej  of  Atmosphere 

Two  Hiirds  Saturated  With  McHSturc 


F. 

28  in. 

29  in. 

f 

30  in. 

|t  in. 

t 

F. 

i8  in. 

29  in. 

30  in. 

31  in. 

0 , 

0.945 

1 0*9* » 

0.882 

0.853 

5* 

19 

1.016 

•98* 

•95* 

1 

•947 

1 -9M 

•884 

•855 

5* 

ix»i8 

•984 

•955 

2 

•949 

; ‘9I6 

.886 

•857 

53 

mm 

1.020 

.986 

•954 

3 

•95 1 

.918 

.888 

•859 

54 

u)58 

1.02  2 

.98B 

.956 

4 

•953 

.920 

.890 

.861  ; 

55 

I.OS4 

•99^ 

5 

955 

.922 

.892 

.863 

56 

! 1-063 

I.Otd 

•99* 

.960 

6 

•957 

.924 

•893 

JftSs 

57 

i/)6j 

1.028 

•994 

j?62 

7 

•959 

.936  ; 

895 

AS7 

58 

1.067 

i4>30 

.996 

•964 

8 

.962 

.928 

•897 

S69 

59 

1.069 

.998 

.966 

9 

-964 

•899 

do 

1.07c 

1.034 

1.000 

.968 

lU 

j^6 

•901 

S72 

di 

1 *-073 

1.037 

1.002 

.970 

M 

.^8 

•903 

•«74 

d2 

1-075 

*•039 

1004 

•97* 

It 

•970 

•905 

.876 

^3 

1.078 

1.041 

i.ood 

•974 

>5 

•972 

•939 

•907 

878 

64 

ixp8o 

1-043 

1.008 

•975 

U 

•974 

•MI 

•909 

i8o 

65 

1.082 

1.045 

ia>io 

•977 

«5 

.976 

•943  ' 

.911 

.88: 

dd 

10264 

*•047 

1.012 

•979 

t6 

.978 

•945 

.913 

.884 

t.086 

1.049 

C.014 

.981 

*7 

.981 

•947 

•915 

886 

68 

tA>51 

1.016 

.983 

16 

.9R3 

•949 

•917 

888 

69 

ijfgo 

1-053 

1.016 

•985 

19 

•^5 

•919 

.S90 

70 

u>55 

1.020 

.987 

30 

-987 

•953 

•9*1 

.891 

7* 

1.091 

*•057 

ia>32 

•989 

U 

•989 

•955 

•9*5 

893 

7* 

*•097  1 

*•059 

1.024 

•99* 

33 

•99* 

•957 

•9*5 

•895 

73 

*•099 

1.061 

1.025 

•995 

»3 

0.993 

^•959 

0-9*7 

0897 

74 

1.101 

1.063 

1.027 

0.995 

•995 

.961 

•9*9 

.899 

75 

1.103 

1.065 

1.029 

.996 

n 

.997 

.943 

•93' 

•901 

7d 

1.105 

1.067 

1.031 

.998 

36 

1.000 

•^5 

•933 

•905 

77 

1.107 

1.069 

1.033 

1.000 

*7 

1.002 

.^7 

•935 

78 

1.109 

t.071 

tj)35 

t.002 

28 

2.004 

.969 

•937 

-907 

79 

r.m 

1.073 

*•037 

1.004 

29 

>.oo6 

.971 

•959 

•909 

80 

1.113 

1 *-075 

1.039 

I £>06 

30 

1.008 

•973 

•95* 

.911 

81 

i 

i.i  16 

*•077 

1.041 

1£>o8 

I.OIO 

•943 

•9** 

82 

1.118 

*•079 

1^43 

I.OIO 

32 

I/>I2 

945 

•9*4 

83 

1J38t 

ij>45 

l£>12 

33 

1.014 

•947 

.9(6 

84 

1.132 

1.083 

*•047 

1.014 

34 

t.016 

.981 

•949 

.918 

85 

1.124 

1.085 

1-049 

l.Otd 

33 

i/h8 

•983 

•951 

Sd 

t.lld 

1.086 

1.051 

1.017 

3^ 

1.021 

.986 

•953 

.922 

87 

Mz8 

1J390 

*•053 

I.OI9 

37 

1 J)2J 

.988 

•955 

•9*4 

88 

1.130 

1.092 

1.055 

l£>2l 

38 

1.025  1 

•990 

•957 

89 

1.132 

**>94 

*•057 

1.023 

39 

1.027 

•99* 

•958 

4)28 

9^ 

1.133 

1.096 

*•059 

1.025 

40 

1.029 

•994 

.960 

•930 

mm 

1.137 

1098 

u^6i 

l£*27 

4^ 

1031 

.996 

.962 

-93* 

9* 

1,139 

(.100 

1.063 

1.029 

4* 

1.033 

•998 

•964 

•933 

93 

1.141 

1.102 

1.065 

■5BI 

43 

1.035 

1.000 

.966 

•935 

94 

I.I45 

I.IO4 

1.067 

BSI 

44 ; 

1.037 

1.002 

968 

•937 

95 

M45 

I.I06 

IX)d9 

i4>35 

4J  , 

T.040 

1.004 

•97<» 

•939 

96 

1.147 

mo8 

1.071 

>•037 

46  1 

t.042 

t.oo6 

' 0-97* 

0.941 

97 

C.149 

1.110 

1.073 

1.038 

47  . 

*•044 

1.008 

•974 

•943 

98 

1.151 

1.1T2 

1.075 

t.040 

48 

(4)46 

1.010 

.976 

•945 

99 

1.154 

1.114 

I £^77 

1.042 

49 

t.048 

1.013 

•978 

•947 

100 

1.13d 

i.ii6 

*-079 

*•044 

50 

1.050 

1.014 

1 

1 -949 

Random  Noixs  on  V'arious  Subjects 


43* 


55.  Cdmidge  Dimension  and  Identification  Tables 

There  are  so  many  standard  factory  loaded  rifle  cartridges,  and 
they  are  so  siiiiilax  tn  appearance  and  d intensions  that  even  when  a 
sample  cartridge  is  known  to  be  a standard  factory  load,  it  is  some- 
times a difficult  matter  to  identify  it  unless  the  markings  on  the  head 
give  the  caliber  and  type. 

In  recent  years  it  has  become  a popular  practice  for  individual 
gunsmiths  or  experinientors  to  modify  standard  factor}'  cartridges 
hy  blowing  them  up  to  fit  a larger  chamber,  or  by  necking  them 
down  to  fit  a smaller  bullet.  As  these  *\vildcacs"  are  usually  made 
from  factory  loads,  the  markings  on  the  case  head  then  become 
meaningless,  and  would  mislead  anyone  except  an  expert. 

With  the  idea  of  aiding  in  the  identification  of  cartridges,  a number 
of  standard  dimensions  of  factory  loaded  cartridges  have  been  sec 
down  below.  'I'hcse  were  prepared  by  first  measuring  a number  of 
actual  .samples,  then  consulting  such  standard  factory  drawings  as 
were  available.  Generali v die  actual  dimensions  found  by  measure- 
ment will  differ  somewhat  from  chose  given  on  rhe  drawings,  because 
a small  tolerance,  or  variation  from  the  exact  figures  is  allowed  as 
a pracricol  manufacturing  necessity. 

Most  modern  center  fire  rifle  cartridges  arc  divided  into  the  four 
classes  of  Rimmed,  Rimless,  Sctni-rimined,  and  Belted,  which  can 
easily  be  distinguished  by  simj^e  inspection.  By  first  placing  the 
cartridge  into  the  proper  one  of  these  classes  the  field  to  be  ex- 
amined is  at  once  narrowed  considerably. 

Next  the  cartridge  should  be  classified  by  caliber,  as  indicated  by 
the  bullet  diameter.  Caliber  is  the  diameter  of  the  unrifled  bore  of 
a gun  in  hundredths  of  an  inch  or  in  inillimeters,  and  the  bullet 
diameter  is  usually  from  .004  to  .008  inch  or  more.  Thus  the  U.  S. 
Rifle  Caliber  .30,  M1903  has  a bore  of  .500,  with  grooves  .004  deep, 
giving  a groove  diameter  of  .308,  and  the  usual  bullet  diameter  is 
.3086.  It  should  be  remembered  that  the  caliber  is  the  diameter  of 
the  bore,  not  that  of  tlie  bulkc.  It  is  therefore  usually  .004  to  .008 
less  than  the  bullet  diameter. 

The  overall  length  of  a cartridge  is  not  a very  definite  measurement, 
as  it  varies  greatly  with  the  type  of  bullet,  so  it  is  not  of  much  use 
for  identification.  For  example,  the  .375  H & H Magnum  with  235 
grain  Open  Point  Expanding  bullet  has  an  uverall  length  of  3.515 
inches,  while  with  the  270  or  300  grain  Round  Nose  Soft  Point 
bullet  it  has  an  overall  length  of  3.600". 

The  case  length,  however,  is  quite  constant,  and  should  be  the 
second  dimension  consulted.  If  the  matter  is  still  in  doubt,  go  to 
the  rim  diameter  next.  This  is,  of  course,  the  diameter  of  the  extract- 
ing rim  at  the  extreme  rear  end  of  the  cartridge  case. 


432 


Hatciifr's  Noit.book 


The  four  classes,  (rim,  rimless,  semi-rim.  and  belted),  into  which  rllie  cart- 
ridges may  be  separated  by  casual  iospectioo. 

Top,  a typical  rimmed  cartridge,  the  6.5fnm  Dutch. 

Second,  the  rimless  6.5mm  Italian  cartridge. 

Third,  the  semi-rim  6.5mm  Japanese  cartridge. 

Bottom,  the  belted  .500  Holland  & Holland  Magnum. 


RhftMed  Cartridges 


Body 


Cartridge  name 

OveraJl 

length 

Case  length, 
inches;  MM. 

length 
head  to 
shoulder 

Rim 

diam. 

Case 
diam. 
at  rear 

Shoulder 

diameter 

Neck  , 
diam. 

Bullet 

diam. 

5.J  n\m  Vclo  Dog  

I.J7S 

1.125 

28.5 

• 

.306 

‘*53 

4 

.150 

.225 

.a  1 8 Bee  



>•345 

34 

•94* 

.408 

•34V 

•iJi 

.242 

-**45 

.zz  Hornet  

l*7i 

140 

35-5 

•8*5 

.350 

•299 

.*78 

.244 

.2235 

.jip  Zipper  

2.260 

1.938 

5«> 

r.36 

.506 

.42  T 

.5^4 

.252 

.2245 

.2  2 Sav,  Hi-Power  

?-5' 

2a>5 

5i 

1.59 

.506 

461 

•357 

•*53 

.227 

.25-20  Winchester  

1.6 

*•33 

33-5 

5I28 

405 

•349 

.329 

.274 

,258 

.20-20  Single  Slioc  



1.633 

1.1 

407 

•3>5 

.300 

.276 

.139 

.25-H  



2.04 

Si 

t-37 

499 

.420 

•355 

.260 

,158 

6.5  mni  NerherlflnJs  

3^5 

2.112 

54 

ij6 

.526 

*448 

42J 

•345 

.i6j 



2.625 

2*375 

60.5 

• 

.380 

.300 

« 

,:Rn 

.258 

.30  W,  C.  F.  (.30-30)  

*.53 

2r>3 

Si 

143 

.fOl 

.418 

.402 

.318 

.308 

7.62  Ruslan  

3^37 

2.114 

54 

M75 

•5?o 

.489 

450 

.336 

.310 

.JO 3 British  

3^5 

2-11 

5^ 

.530 

•456 

402 

•337 

.311 

.30-40  Krag  



2.314 

60 

*•7 

•545 

457 

415 

.338 

,308 

.ji  W.  C.  F.  (.32-20)  

t-59 

1.315 

33-5 

^3 

405 

•353 

-jj8 

.326 

.312 

8.15  X 46  R 

l4^i 

46 

• 

481 

.419 

4 

•344 

.330 

B mm  Austrian  

3,000 

>•90 

50 

1,514 

•554 

492 

462 

•345 

•3*3 

9 inni  Lcbel  

2*967 

*•99 

50 

*457 

•^34 

•543 

45^ 

.350 

•5*3 

.32  Win.  Spl 

t*55 

ii)6 

Si-S 

*44 

.500 

4*9 

•396 

.340 

,318 

.32-40  Winchester  

2.5U0 

2.193 

56 

• 

.506 

,424 

,338 

.321 

8x57  R 

3*55 

1.24 

57 

1.84 

486 

4*9 

-375 

.326 

.318 

8 mm  Danish  Krag 

3^ 

2.281 

58 

1.635 

•575 

.550 

457 

•355 

•3*5 

.J3  Winchester 

2-795 

2.105 

53-5 

1-570 

.6(0 

.508 

-443 

-365 

•3385 

.548  Winchester  

2.70s 

2.255 

57*5 

iiS50 

.6(0 

•555 

.485 

•375 

.548 

Rhnmed  Cartridges 


Cartridge  name 

Overall 

length 

Case  length, 
inches;  MM. 

length 
head  to 
shoulder 

Ran 

diam. 

Case 
diam. 
at  rear 

Shoulder 

diameter 

Neck 

diam. 

Bullet 

diam. 

.38  W.CP.  {. 38-40)  

*.595 

1.307 

33 

•908 

.518 

.466 

430 

4*4 

.400 



:j6oo 

a.112 

44 

t.ito 

.603 

.500 

44* 

.402 

•375 

,38-55  Winchester  

2487 

s.i  29 

54 

.506 

420 

.392 

•3775 

9-J*7»R  

3.410 

2.834 

^ J 

r 

-♦83 

426 

% 

.384 

•3675 

^-6c  

2.250 

1.875 

48 

f 

.618 

.503 

• 

4*6 

408 

^-82  W,  C F 

2.765 

2.390 

61 

.610 

.508 

457 

4*7 

.408 

ym 

2.583 

66 

•543 

46t 

# 

436 

4H5 

44  VV,  C F.  (44-+0)  

1.59a 

1.305 

33 

•5*5 

.4?  I 

•443 

4*9 

.45-70  

2.15 

54 

* 

.600 

.500 

• 

475 

457 

■95  .*5  

2.80 

2.40  61  * 

Belted  Cartridges 

.60Z 

.501 

• 

475 

457 

.300  HfiiH  Magnum  

5.6cm> 

2^50 

241 

•53* 

•5‘3 

430 

.338 

.3088 

.375  II&II  Magnum  

3.600 

a.85  7*  2.41 

SevthRwmed  Cartridges 

•53* 

•5»3 

.430 

404 

•3755 

6.J  nim  Japanese  

34» 

IM> 

5* 

t.58 

476 

•449 

4*4 

.491 

•26a 

.280  Ross  

5-48 

66 

2.185 

•556 

404 

•3*3 

.286 

.303  Savage  

1.52 

2^015 

5* 

1.300 

.505 

•44* 

.390 

•553 

.308 

7.7  Jap.  Hvy  MG 

3'5 

2.280 

58 

1.89 

499 

47* 

431 

•53® 

.311 

.31  Win.  S.  T 

iJSS 

M4 

33 

• 

.390 

•349 

4 

•547 

.321 

.J5  Win.  S.  L 

1-6) 

1.154 

# 

405 

.362 

•377 

•35* 

,351  Win.  S.  L 

1.90 

1.38 

35 

• 

410 

.380 

• 

•377 

•35* 

.40 1 Win.  S.  L 

2.005 

1.50  aS  * 

Rimless  Cartridges 

490 

•433 

•43* 

.407 

.210  Swife 

2.68 

2.20 

56 

J75 

47* 

443 

•39* 

.260 

.224 

5.^  mm  Vom  Hofc  Super  Express  . . 

j'48 

2^ 

6( 

<75 

477 

479 

.450 

.258 

.226 

6 mm  U.  S.  N 

3-»* 

2.36 

60 

1.76 

44.3 

4411 

-394 

.276 

•2435 

.250-3000  Savage  

2.515 

1411Z 

49 

I-5* 

.470 

.4686 

405 

.2856 

•*57 

.i$  Remington  

2.55 

14)5 

S* 

1.50 

-4*9 

4*7 

.596 

.286 

.158 

6-5  mm  Italian  

3JX) 

2nrt 

525 

1^34 

447 

'447 

425 

.295 

.2655 

6.5  mm  Mannlicher  

JA2 

2.12 

54 

1,69 

450 

44: 

.425 

.295 

.2625 

6.5  mm  Norway  Krag  

3M5 

2.158 

55 

<•7 

479 

478 

430 

.28) 

.262 

6.5  Swedish  

309 

2.16 

55 

1.76 

477 

47* 

43* 

,397 

.264 

6,5x57  mm  Mauser  

VV 

2.2) 

57 

1.72 

4d4 

.4665 

425 

.296 

.262 

.257  Rem.  Roberts  

37 

f.72 

•47) 

'47' 

43* 

.290 

•*575 

.276  Pedersen  

2.84 

24>2 

5* 

1.68 

44^ 

448 

•3S3 

•3*1 

.284 

7 X 57  min  Mauser 

3*00 

2.2)5 

57 

1.71 

474 

.47} 

.420 

,320 

.384 

2.540 

^3 

1-949 

473 

47^ 

•44* 

.308 

.278 

•JO  \J.  S.  Qcbine  Mi  

1A7 

1.288 

33 

.356 

354 

• 

«33* 

>30$ 

.300  Savage  

i.«7 

475 

•S> 

468 

.468 

'443 

•3)3 

•308 

.30  Remington  

2.51 

2.05 

5* 

1.50 

418 

4*7 

•39^ 

•329 

.307 

7*t  min  French  M29 

^•995 

2.124 

54 

1-7 

484 

.481 

438 

•34* 

•307 

7.54  mm  Swl«  

34)44 

2.19 

'•7i 

495 

494 

•45« 

•335 

.3065 

7^5  mm  Relgian  

34J4 

2.(0 

5V5 

1.76 

47* 

47* 

411 

•34* 

.)X0 

7.7  mm  Japanese  

2.28 

t.89 

474 

471 

43* 

•338 

.311 

.3g-*o6  U.  S.  Gov’c  

hiyo 

2-494 

i.94» 

4^ 

466 

433 

.3086 

,30  Newton  

*•495 

^3 

24)00 

•5* 

•5*5 

,503 

.340 

•3075 

7,9  Ger.  Carbine  

1.85 

1.298 

)) 

•955 

469 

469 

440 

•35* 

•3*3 

8 X 51  Shore  Smokeless  ... 

*•77 

l.Ot 

3« 

1.525 

4<^7 

.467 

43>" 

•344 

.318 

.32  Rcnmigtoii  

^•54 

2.06 

5* 

1.51 

.418 

418 

•394 

•34* 

.)2* 

8 X 56  mm  Mannlicher-Schocnaticr  . . 

34)40 

2.218 

56 

1.71 

47) 

467 

•4*3 

•55* 

•323 

7.9  mm  (8  mm)  Mauser  

3'7 

2.24 

57 

i.8z 

47) 

470 

•433 

•549 

•3*3 

.35  Remington  

1.52 

1.92 

49 

*•53 

457 

454 

419 

.4045 

•359 

9 X 56  mm  Mann-Sch 

3.56 

2.215 

5^5 

1.8)2 

.464 

.464 

408 

•378 

•354 

10.75  X 68  

3.16 

2.669 

68 

iJJ73 

4S8 

.492 

470 

445 

422 

*Ca5C  has  no  shoulder. 


(See  supplement^  information  on  page  ^09). 


43  <>  H atcher’s  Notebook 

Sta?idard  Headspace  Dimeitsions  for  Various  Cartridges 

Rhfm/ed  Cartridges.  These  have  hcails,  or  rims,  which  arc  larger 
in  diameter  than  the  main  body  of  the  cartridge.  When  such  a cart- 
ridge is  seated  in  the  chamber  of  a gtin,  the  rim  is  what  limits  its 
forward  motion  and  holds  it  in  firing  position.  A space  or  opening 
must  of  course  be  provided  between  the  front  of  the  breech  block 
or  bolt  and  the  rear  of  the  barrel,  for  the  cartridge  rim  to  fit  into, 
and  this  opening  is  called  the  headspace.  Standard  figures  for  rim 
thickness,  headspace,  bore  diameter*  and  bullet  diameter  for  various 
well  kmjwn  rifle  cartridges  arc  given  below. 


Name  of  cartridge 

Rim  thick- 
new.  Max. 

Headspace 
Mini-  Maxi- 
mum mum 

Standard  Bullet 

Bore  Diameter 
Diameter 

.22  i-ong  Rifle  Rim  Fife  . . 

-044" 

•044" 

- 

.217’' 

.225" 

.21$  Bee  

* 

,o6s^ 

•^5'' 

- .069'’ 

.219" 

.2245" 

.219  Zipper  

4 

- 4^67" 

.219'' 

.2245- 

,22  Home:  

4 

•<^5" 

- 4)69" 

.217- 

.«35" 

,12  Savage  Hi-P<jwer  

4 

- 4KS9" 

.111" 

.226" 

,25-35  C.  F 

4 

.250" 

.258" 

.jo  W.  C.  F.  (.30-30)  •... 

4 

.063^ 

- 4367- 

,300" 

.308" 

.30-40  Krag 

• 

.064' 

.064 

- ^7^' 

.3088" 

7.^2  mm  Russian 

.064" 

.064" 

4j6H" 

.310" 

.303  Savage  

• 

Ms*" 

- /irtg'' 

.300'' 

.308" 

.303  Bnthh  

.o6f 

•064" 

- .067" 

.303" 

.312- 

.32  W.  C.  F.  (.32-20)  .... 

• 

X)6s' 

•065" 

- 4)69" 

.305'' 

.32  Will.  Spl 

• 

.od3^ 

- 4X17" 

.315" 

.322^' 

.32*40  Winchester  

4563" 

.315“ 

.321" 

8 mm  Lebel  

4 

-070*' 

•079" 

- ^3" 

.314“ 

.323" 

.33  Winchester  

4 

.070" 

*070" 

- 4)74* 

.330" 

.3385" 

.34$  Winchester  

4 

4570" 

- -074" 

.340'' 

•348" 

a ^ ^ 4 « 44  4444 

4 

4j6r 

.359" 

.38-55  Winchester  

4 

-4)67" 

.37J" 

•3775" 

.40-82  W.  C.  F 

4 

.070* 

- 4J74" 

.402" 

4221" 

.405  W.  C.  F 

# 

•07J' 

-oTB" 

— 4>7d” 

.405" 

413?" 

,44  W.  C F.  (.44-40)  

4 

.065' 

4x55" 

- 4)^'’ 

4225" 

428" 

* Bore  diameter  means  the  dbmeter  of  the  un rifled  bore,  and  is  generally  the 
same  as  the  caliber.  There  are,  however,  some  caliber  iiaJiies  that  have  been  given 
for  special  reasons,  which  diJfcr  from  this  role.  For  example  the  .257  Remington 
Roberts,  which  is  really  n .25  cnlil»er  wa.s  nan>ed  for  die  bullet  diameter  to  diS' 
cinguish  ic  from  other  experimeatal  .25  caliber  cartridges  of  similar  design. 

Rimless  Cartridges,  Many  of  the  modem  high  powered  rifle  cart- 
ridges are  made  with  a groove,  or  cannelure,  for  the  extractor  to  fit 
into,  and  the  rim,  or  head  of  the  cartridge  is  no  larger  in  diameter 
than  the  body  of  the  case  near  the  head.  As  there  is  no  rim  to  limit 
the  forward  motion  of  such  cartridges  when  they  are  pushed  into 
the  chamber  of  the  gun,  they  seat,  or  come  to  rest  with  the  forward 


437 


Random  Noixs  on  Various  SuDjtcis 

shoulder  of  the  carrridgc  case  bearing  against  a similar  tapered 
shoulder  or  cone  in  the  chamber.  When  this  sv'sieni  of  scaring  the 
cartridges  is  used,  the  distance  from  the  face  the  breech  block 
in  the  locked  position  to  some  definite  measuring  point  on  the  conical 
shoulder  of  the  chamber  is  called  the  “headspace,"  though  in  fact 
it  is  not  strictly  space  at  all,  but  rather  cartridge  space. 

Some  rimless  cartridges,  such  as  chc  .30  caliber  carbine  cartridge 
and  the  .45  automatic  pistol  cartridge,  are  nearly  cylindrical,  and 
have  no  such  shoulder.  In  such  cartridges,  the  front  end  of  the  case 
is  left  square,  so  that  it  can  seat  against  the  slight  ledge  or  shoulder 
at  the  front  of  the  chamber. 

The  tabulation  which  follows  gives  the  minimum  headspace  dimen- 
sions for  some  of  the  better  known  bottlenecked  rimless  cartridges, 
together  with  the  angle  of  the  chamber  cone,  the  reference  diameter 
on  the  cone  to  which  the  headspace  is  measured,  and  other  interesting 
dimensions. 

While  only  the  minimum  headspace  is  given,  the  maximum  may  in 
general  be  taken  as  .004"  greater  than  the  minimum.  These  figures 
are  for  new  guns.  The  headspace  may  be  expected  to  increase  slightly 
with  use.  If  the  headspace  becomes  excessive,  the  cartridges  will  tend 
CO  stretch  or  even  separate. 


Najiie  of  cartridge 

Body  taper 
per  inch 

Angle 
between 
center]  ine 
of  chamber 
and  wall 
of  cone 

Ref- 

erence 

diam- 

eter 

on 

cone 

Head- 
space, 
breech 
face  CO 
reference 
dia.,  min. 

Bore 

diam- 

eter 

Bullet 

diam- 

eter 

.220  Swift*  

, . ,0282'' 

21® 

•335" 

1.806" 

.219" 

.224s" 

.2j  Remington  .... 

n* 

•375*' 

1.5286® 

.250" 

.250*3000  Savage  . . 

*04^92'" 

26*  30' 

1.5792" 

.250 

.^57" 

.257  Rem.  Roberts 

.027278" 

20®  39' 

.375^ 

'•7937" 

.250" 

•^575" 

.270  W.  C.  F 

. .01658" 

17*  T5' 

•375** 

20479" 

.270 

.278" 

7 mm  Mauser  .... 

.027278" 

20*  59' 

.375" 

i«7937" 

.276" 

.284" 

.30  Remington  .... 

^3* 

.3626" 

1.5432" 

.300'’ 

.307" 

.300  Savage 

..  .01768" 

.3968" 

1,5967" 

.300* 

•5085" 

.30-06  U.  S.  Gov't 

4>i65" 

17®  13' 

•44*5" 

1.940” 

,300” 

.3086" 

7.9  (8  mm)  Mauser 

X12386" 

20®  48'  25" 

.375" 

r.fi96" 

.311" 

8 mm  Mann.-Schoen.  .022642" 

22®  04' 

•375' 

1.866" 

.31a" 

•323 

.32  Remington  

, . .015161" 

23® 

.575" 

C.5286" 

.312" 

.321" 

.35  Remington  .... 

. .023529" 

23®  25' 

4117" 

1.5504” 

•349" 

.359" 

“Note:  The  .220  Swift  is  a.  sort  of  half  breed;  a semi-rim  cartridge  which 
doesn't  use  its  rim  to  seat  on,  as  do  aU  the  other  semi-rim  cartridges,  but  instead 
leaves  it  hanging  out  in  the  air  and  seats  on  che  Moulder  instead.  This  cartridge 
was  developed  from  the  old  6 mm  U.  S.  Navy  case,  with  the  extractor  cue  and 
rim  made  larger  in  diameter  allow  more  met^  in  the  head  and  strengthen  this 
weak  point  in  the  case. 

(See  fupplcmental  information  an  page  T09), 


Hatcher’s  Notebook 


438 

Semi-Rimmed  or  Stmi-Rimless  Cartridges.  At  first  glance  these 
look  like  rimlebs  cartridges.  They  have  a groove,  or  cannelure  for 
the  extractor  to  hook  into,  and  the  extracting  riin  appears  to  be  about 
the  same  size  as  the  rear  end  of  the  cartridge  case  body.  However, 
on  close  examination  the  rim  will  be  found  to  he  just  sliErhtly  larger 
than  the  rear  of  the  case  body,  and  this  slight  enlargement  is  enough 
for  the  cartridge  to  scar  against  when  it  is  chambered,  just  as  the 
rimmed  cartridge  seats  against  the  rim- 


mx.  C TG. 


^ I 


^1.902 

Af/N.  CHAMBER 


Maximum  case  and  minimum  chamber  lor  the  German  service  cartridge,  7.92 
X S7mm  J,  drawn  to  hhistraie  the  standard  method  of  showing  the  headspace 
measurement  in  rtmle&s  botile-nedted  rifle  caricidges.  Headspace  is  measured 
from  the  iocatlun  of  the  bolt  face  in  the  locked  position  to  a stated  diameter  on 
the  cone  of  the  chamber.  In  this  instance,  the  cone  has  an  angle  of  20°'48  *25'', 
and  the  .373"  diameter  on  this  cone  is  ljM)l  inches  from  the  bolt  face  when  the 
gun  has  minimum  headspace. 

In  the  cartridge  designation  7.92  x S7mm  Jj  the  6rst  figure  is  the  bore  dia- 
meter, the  second  is  (be  length  of  (be  case  without  bullet,  and  the  J stands  for 
Infoncrv  (Jnfancetie),  showing  that  it  is  an  Army  cartridge. 


In  semi-rim  cartridges,  the  headspace  is  the  distance  from  the  face 
of  the  bolt  or  breechblock  in  the  closed  position  to  the  seat  against 
which  the  rim  of  the  cartridge  seats.  Rim  thickness  and  other  dimen- 
sions for  some  semi-rim  cartridges  are  given  below. 


Random  Notfs  on  Various  Subjkcts 


439 


Name  of  canridge 

Rim  diidmess 

Headspace 

Min.  .Vlax. 

Standard 
bore  diam. 

Bullet 

diam. 

6.5  mm  Japanese  M . 

J06" 

.25A" 

.262'' 

.280  Ross  

. . . .0^2^ 

.280" 

.286" 

.303  Savage  

.300" 

.508" 

77  Japanese  H.  M.  G.  . 

.oA" 

.305'' 

.311" 

.32  Win.  Self  Loading  . 

. . . x>5"  max. 

•05" 

.315" 

.322" 

.^5  Win.  “ 

u>5*  " 

415" 

•34^ 

•35»" 

.351  Win.  “ 

pf  a 

*05 

^5" 

'345" 

.35^" 

.401  Win. 

dipe  a 

• . . • *o6 

4)6" 

.407" 

Belted  Cartridges,  These  have  a very  thick  seating  rim,  or  belt,  at 
the  rear  of  the  case,  with  the  extractor  groove  cut  into  the  rim 
itself.  The  headspcc  is  the  distance  from  tSie  face  of  the  bolt  when 
it  is  lucked,  tu  the  ledge  in  the  rear  part  of  the  chamber  against  which 
che  belt  of  the  cartridge  sails. 

Headspace  and  some  other  dimensions  are  as  follows: 

Belt  thickness  I letdspace 

Name  of  cartridge  Max.  IVlm.  Max.  Bore  diani.  Bullet  diam. 

.500  IT&II  Magnum  ...  .220'  .2io"-.«3'*  .^oo"  .joHS" 

.375  H&H  Magnum  ,..  •no'*  .366"  *3755'' 


'I'able  of  Normal  Bore  and  Bullet  Sizes 
In  general  the  bore  diameters  given  below  are  intended  to  represent 
the  normal  minimum  and  the  bullet  diameters  the  normal  maximum 
standard  sizes. 

The  figures  given  below  were  obtained  both  from  measurements 
of  samples  and  by  reference  to  standard  drawings,  checked  one 
against  the  other.  Wide  variations  betw'een  the  measurements  of 
individual  sampleis  of  the  sati>e  cartridge  were  sometimes  encountered, 
and  occasionally  these  measurements  did  not  agree  very  well  with 
the  standard  figures  as  given  on  the  drawings.  These  discrepancies 
were  adjusted  as  far  as  possible  to  ^ive  what  may  be  taken  as  normal 
representative  figures  /or  ihc  cartridges  mentioned. 


Name  of  cartridge 

.22  Long  Rifle  Rim  Fire 

.218  Bee  

.219  Zipper  

.22  Hornec  

,22  Savage  Hi-Fower  

.220  Swift 

5.5  mm  Velo  Dog  

5.6  mm  Vom  Hofe  Super  Kxpress 

6 mm  IT,  S.  N.  


Normal  Normal 

minimum  maximum 

bore  diameter  bullet  diameter 


.225'' 

.219" 

.2245 

.219- 

.2245 

.217" 

•2235 

.221" 

•227" 

.2.9- 

.224" 

.217'' 

.225" 

.aao"* 

.226" 

.23A'' 

•2435' 

Hatcher’s  Kotf.rooic 


440 


Normal 

Normal 

minimum 

maximum 

Name  o£  cartridge 

bore  diameter 

bullet  diameter 

.2^  20  Single  Shoe 

.2f0" 

,2<6" 

.25-20  Repeater  

.250- 

.256" 

.25-25  

.250" 

,2t8" 

•25-35  •. 

.250- 

.25  Reiiiliigtnn  

.150'' 

.258" 

.2S0-5000  Savage  

.250- 

.257" 

.25^  Remington  Roberts  

.250" 

•2575'' 

^.5x54  mm  Mannlidier  

.256- 

.2626" 

6,5x57  mm  Mauser  

.256" 

.262" 

6.5  mm  Japanese  M 58  

.262" 

6.5  mm  Italian  Service  

.256" 

6.5  iimi  Norwegian  Krag  

.256'' 

.262" 

6.5  mm  Swedish  

.256" 

.264'' 

6,5  mm  Netherlands  

.256" 

.:63" 

6.5  mm  Roumanian  

.256" 

.263" 

.270" 

.278" 

.276  Pederwn  

.27^" 

.284" 

.180  RofiS  

.:8o" 

.2H6" 

7x57  mm  Mauser  

•2755" 

.284" 

7.5  mm  French  M 1929  

•295" 

7.54  mm  Swiss  

•297" 

.3068" 

7^5  nmj  Belgian  

.295" 

.3x0'' 

.30  W,  C.  F.  (.30-50)  

.300" 

.308'' 

.\n  Rernlngfon  

•3<x)" 

.30  Cftl.  U.  S,  Carbine  Mi  

.300" 

.308" 

.30-40  Krag  

.300" 

.3088" 

.30-06  U.  S.  Gov’t  

.300" 

.3086" 

.30  Newton  

.300" 

.3075" 

.300  Savage  

.300'* 

.308'' 

.300  H&H  Magnum  

.300" 

.3088" 

7.61  mm  Russian  

.JOft" 

.3tn” 

.303  Savage  

.joo" 

.308" 

.303  British  

•3«.r 

.3ir 

7.7  Japanese  M 99  

.303'' 

•ixx" 

.32  W.  C.  V.  (.32-20)  

•505" 

.5x2" 

.32  Remington  

.31.” 

.32  Winchester  Special  

•5»5" 

.322" 

.32-40  Winchester  

.321" 

.32  Winchester  Self  Loading  

•5<5'' 

.322" 

*7,9  mm  X 57  mm)  German  Spitzer  

.312' 

•323" 

•7.9  mm  (8x57  mm)  Old,  Rotind  Nose 

.312" 

.318" 

*8  X 57  mm  Remington  make  lor  M *88  & M ’98 

.312- 

•523" 

8x57  R (Rimmed)  

5>*' 

.318- 

8 x56  mm  Mannlichcr-Schocnauer  

.512" 

.323" 

8x51  Shore  Smokeless  

.310" 

.318" 

8 mm  Austrian  M.  ’95  

.312'' 

.3228" 

8 min  Danish  Krag  

-5*4" 

•325" 

8 mm  I.ebel  

•5*4" 

•321" 

8.15x46  R 

.321" 

,3^o"-.3i8"  (step) 

•35  Winchester  

.550" 

.5385" 

Random  Notes  on  V’arioiis  Surjf-CTS  441 


Name  of  cartridge 

Normal 
minimum 
bore  diameter 

Normal 
maximum 
bullet  diavnerer 

.348  Winchester 

340” 

.348" 

.55  Winchester  Self  Loading  

345” 

•35'" 

.351  Winchester  Self  Loading 

34j" 

•35'" 

.35  Remuigtoii  

349" 

•359" 

.375  H&H  Magnum  

3«" 

■3755" 

-j8  W.  C.  F.  (.38.40)  

394" 

.400" 

.38-55  Winchester  

573" 

.3775" 

•38-5«  

57«” 

.375" 

9 x56  mm  Mannlichcr-Scbocnnucr  . 

346” 

.354" 

9.3x7:  mm  R 

5<o: 

•3675" 

40-60  

400 

■w" 

40-82  W.  C.  F 



408" 

401  Winchester  Self  Loading  .... 

ms 

•407' 

405  W.  C.  F 

-405" 

41 '5" 

44  W.  C.  F.  (.44-40)  

-4»5" 

■4»7" 

•45-70  

450 

457 

•45-8$  

45«" 

4575 

* German  Service  RiDe  M '89  has  bore  groove  Jiamctcr  and  used  chc 
old  7.9  mm  service  cartridge  having  a buUci  weighing  .U7  grains  and  with  a di- 
ameter of  .318.  The  German  Service  RiAe  M has  a bore  of  .312  and  a groove 
diameter  of  .3256,  and  uses  the  Spitzer  bullet  weighing  154  grains  for  the  older  flat 
based  type,  and  197.5  fof  (he  later  boat  tailed  type,  and  both  have  a 

diameter  of  .323  The  hunting  bullet  made  ki  America  lor  use  In  both  these 
rides  has  a bullet  weighing  170  grains  and  having  a diameter  of 
Numerous  warnings  have  been  printed  against  firing  the  7.9  mm  Spicter  Service 
load  in  the  old  M ^88  German  Rifles,  which  are  not  as  strong  as  the  M ’98 
Mausers.  So  don't  fire  the  German  mm  Spitaer  pointed  service  ammumdon 
in  the  old  Gew.  *88,  nr  in  commercial  rifles  made  on  that  model. 


XVIII 


Record  of  Accidents  to  the  U.  S.  Rifle 
Cal.  .30,  M1903.  1917  to  1929,  Incl. 

During  the  years  from  1917  to  1929  inclusive,  there  were  137  acci- 
dents CO  the  U.  S.  Rifle,  Cal.  .30,  M 1903  reported  and  made  of  record, 
the  details  of  which  are  given  below.  Tlicsc  accidents  were  as  follows: 


Burst  receiver  68 

Blow  back  23 

Burst  barrel  due  to  obstruction  21 

Burst  barrel  due  to  weak  or  seamy  metal 13 

Burst  barrel  due  to  burnt  steel  10 

Hangfire  while  opening  bolt i 

Nature  of  damage  not  stated i 


Burst  Receivers.  This  accident  js  usually  caused  fay  a failure  or  open-^ 
iiig  up  of  the  cartridge  head,  resulting  from  high  pressure  or  soft  brass, 
thus  allowing  the  gas  under  high  pressure  to  gee  out  into  the  action. 
If  the  receiver  is  weak  or  brictle,  it  may  then  rupture.  These  68  burst 
receivers  caused  personal  injuries  as  follows: 


Loss  of  an  eye  3 cases 

Injury  described  as  serious  3 “ 

Injury  described  as  severe  3 “ 

Injury  described  as  slight  27  “ 

Injury  not  mentioned  25  “ 

Definite  report  of  “No  Injury”  7 “ 


If  shooting  glasses  had  always  been  worn,  it  is  reasonable  to  assume 
that  many  of  these  injuries  would  have  been  prevented  or  reduced  in 
severity. 

All  but  two  of  these  accidents  definitely  occurred  with  receivers 
having  the  old  heat  treatment  used  in  Springfield  and  Rock  Island 
so-calJcd  low  numbered  receivers;  that  is,  below  No.  800,000  and 
No.  285,507,  respectively.  A Rock  Island  receiver  reported  as  No. 
445,136  blew  up  in  1918,  and  w'as  later  recorded  in  War  Department 
records  as  the  failure  of  a high  numbered  receiver;  but  it  now  develops 
chat  the  number  reported  must  have  been  in  error,  as  the  last  receiver 
made  at  Rock  Island  in  1918  was  numbered  around  380,000,  and  re- 
ceiver No.  445,136  was  not  made  until  about  May,  1919.  A mistake  of 
this  kind  is  quite  easy  ro  make,  as  when  the  receiver  is  shattered,  the 


442 


Record  of  AixnDENXs 


number  is  often  blo>vn  parr]y  or  entirely  and  may  have  to  be 
pieced  together  or  more  or  less  guessed  at. 

The  only  other  case  recorded  as  the  bursting  of  a receiver  having 
the  improved  heat  treatment  was  Springfield  receiver  No.  801,540, 
which  blew  up  in  1929  as  the  result  of  firing  a 7.9  mm  German  car- 
tridge. If  is  highly  doubifnl,  however,  that  this  was  actually  a receiver 
of  the  improved  heat  treatment,  for  the  exact  serial  number  of  the 
first  of  the  new  series  is  not  known  with  certainty.  It  is  only  known 
due  this  treatment  was  started  at  about  the  date  on  which  receiver 
No.  800,000  was  being  made,  and  as  over  1,000  receivers  a day  were 
being  made,  an  error  of  two  days  in  the  estimated  date  would  make 
the  difference. 

Of  the  d8  burst  receivers  reported  there  were  11  instances  where 
the  serial  number  either  was  not  recorded  or  could  not  be  ascertained 
with  certaintv’.  Of  the  remaioii^  57  receivers,  53  were  made  by 
Springfield  and  24  by  Rock  Island. 

Thus  out  of  a total  of  800,000  low  numbered  Springfield  receivers, 
there  were  33  reported  bum  in  13  years,  or  about  i in  24,242.  Of  the 
285,507  low  miTTihered  Rock  Island  receivers,  there  were  24  reported 
failures,  or  about  i in  1 1,896.  This  does  not  of  course  take  imo  account 
the  unidentified  ones,  or  those  which  may  not  have  been  reported 
at  nil. 

The  actual  serial  numbers  of  the  receivers  reported  as  having  frac- 
tured were  as  follows  (omitting  the  Rock  Island  receiver  erroneously 
reported  as  No.  445,136,  real  number  uncertain): 

Springfield  Armory'  Make  Rock  Island  Arsenal  Make 

Nos.  Nos. 


4^5,076 

468,300 

204,861 

70,97' 

501,719 

lot, 200 

2i7>794 

84,684 

560,852 

104,926 

2i3i235 

89,720 

590,480 

108,448 

225,764 

89,728 

625,587 

1 I 2,62  1 

234,466 

173,807 

^>?4’479 

146,184 

235>742 

195,082 

642,675 

146,554 

2 39i754 

200,572 

642,742 

165,282 

240,914 

206,331 

656,701 

170,805 

250,560 

228,1  12 

662,284 

1771232 

2531241 

2357504 

666,263 

203,851 

262,165 

2747272 

7"t253 

284,086 

7'2,763 

299,458 

723><575 

312,249 

770,160 

326,222 

801,548 

486,640 

444 


Hatcher’s  Notebook 


It  is  almost  startling  to  note  how  sharply  the  feikires  stop  about  the 
numbers  marking  the  change  in  heat  creatinent,  that  is,  at  approxi- 
mately No.  800,000  for  Springfield  and  No.  2^51507  for  Kock  Island, 
in  spite  of  the  fact  that  the  record  continued  for  twelve  years  after 
this  change  in  heat  treatment  went  into  effect. 

It  is  also  interesting  to  note  that  at  least  4 of  the  receiver  failures 
were  due  to  the  firing  of  a German  7.92  mm  cartridge  in  the  Spring- 
field  Rifle.  A case  will  also  be  found  where  such  a German  cartridge 
was  fired  in  a Springfield  Rifle  having  the  impnwed  heat  treatment^ 
with  no  injur)'  to  the  receiver. 

Another  fact  that  will  bear  noting  is  tliat  tw'o  of  the  receiver  failures 
recorded  were  caused  by  firing  the  guard  cartridge,  which  is  supposed 
ro  he  loaded  to  extreme] v low  pressure  and  velocity.  These  Guard 
cartridges  used  the  regular  150  grain  bullet  with  9.1  grains  of  Bnllseyc 
Powder,  CO  give  a muzzle  velocity  of  1100  feet  per  second.  The  fail- 
ures may  have  been  caused  by  the  fact  that  w'hile  the  pressure  of  this 
small  charge  of  Bullseyc  is  vcr\'  low,  still,  this  is  an  extremely  c]uick 
powder,  and  the  umtsually  sudden  application  of  the  shock  may  have 
been  too  much  for  the  glass-hard  metal.  Of  course,  on  the  other  hand, 
a double  or  triple  load  might  have  occurred  by  some  accident.  This 
would  of  course  give  a verv  high  pressure,  nowever,  1 am  inclined 
to  lav  the  cause  of  the  trouble  to  the  sudden  character  of  the  powder 
rather  than  to  high  pressure,  as  when  I investigated  one  t)f  these  two 
cases,  1 noted  particularly  that  the  metal  showed  no  distortion  or 
stretching  at  all,  and  the  explosion  exhibited  very  little  energy.  When 
the  user  fired  the  guard  cartridge,  the  pieces  of  the  receiver  simply 
fell  CO  the  floor  as  they  might  have  done  if  ic  had  been  made  of  glass 
and  had  been  struck  with  a hammer. 

B/ou*  Backs.  When  the  head  of  rhe  cartridge  fails  as  dcscrihed  above, 
and  the  receiver  is  too  strong  to  be  fractured,  the  escaping  gas  usually 
breaks  the  flanges  off  the  front  edge  of  the  holt,  blows  out  or  bends 
the  extractor,  and  bulges  the  magazine  well.  The  stock  may  also  be 
more  or  less  split  and  splintered  around  the  magazine.  The  principal 
danger  to  the  shooter  is  that  he  may  get  powder  grains  or  particles  of 
brass  in  the  eyes;  this  can  largely  be  prevented  if  he  has  on  shooting 
glasses. 

An  cxaminaciun  of  the  reports  slwws  tliat  there  were  23  accidents 
that  w'ere  essentially  cartri^e  head  blow  backs,  though  they  are 
described  by  various  terms.  .Many  of  these  which  occurred  with  re- 
ceivers of  the  improved  heat  treatment  would  no  doubt  have  resulted 
in  hurst  receivers  if  the  heat  treatment  had  been  of  the  older  type.  In 
two  cases,  the  receivers  of  the  improved  heat  treatment  were  damaged 
hv  such  an  incident.  One,  No.  946,508,  w’as  “deformed,*’  while  another. 
No.  951,718,  was  “bulged.”  However,  these  improved  receivers  held 
together  and  did  not  fracture. 


Record  of  Acodents 


44J 


Ir  is  HOC  uncommon  for  a blow-back  of  the  kind  described  above  to 
be  reported  as  a malfunction  of  the  boir,  as  the  thin  flanges  at  the  front 
end  of  tiie  bolt  arc  usually  broken  off.  For  example,  March  17,  192S, 
with  rifle  No.  SA  276,rS9t,  it  was  reported  that  “One  side  of  the  face 
of  bole  blown  off,  handle  had  to  be  driven  up  to  extract  cartridge.” 
Again,  Summer  of  1927,  rifle  SA  201,595  ‘"Bolt  blew  our,  no  damage 
CO  rifle  proper— no  mention  of  anv  injuries.*’  This  no  doubt  means 
simply  char  the  bolt  blew  out  around  the  front  edges,  but  the  wording 
is  such  that  the  reader  might  verv  well  conclude  that  the  entire  bolt 
was  driven  out  of  the  rccefvcr. 

Hurst  Barrels.  Barrels  may  burst  from  firing  the  gun  with  an  ob- 
struction in  the  bore,  which  happened  in  21  of  the  cases  reported 
herein;  from  seamy,  weak,  or  defective  metal  in  the  barrel,  which 
happened  in  13  cases;  and  from  hnrnr  steel  in  the  butt  end  of  the 
barrel,  caused  by  hearing  the  barrel  blank  coo  hoc  in  the  upsetting 
operation. 

Unlike  hurst  receivers,  which  occur  only  in  low  numbered  rifles, 
burnt  barrels  usually  occur  only  in  high  numbered  rifles,  or  in  low 
numbered  guns  that  have  been  rebarrcllcd. 

In  die  carlv  Springfield  producrion,  the  Armory'  made  their  own 
haiTcl  blanks  by  rolling  bars  of  steel  in  tapered  rollers,  so  as  to  make 
the  bars  thinner  at  the  nnir/lc  end  and  thicker  at  the  breech.  When 
production  was  stepped  up  at  the  beginning  of  World  War  I,  Spring- 
field  Armory  started  buying  barrels  from  an  outside  source.  I'hcse 
barrels  were  made  by  taking  bars  of  uni  f uni  1 size  and  upserring  one 
end  after  heating  it  ver\'  hot.  to  make  the  thicker  breech  section.  Some 
of  these  barrels  were  heated  too  hot  in  this  process,  with  the  result 
chat  the  steel  in  the  breech  section  was  burnt,  and  became  very  weak. 
Several  failures  of  this  kind  occurred  in  barrels  made  bv  the  Avis  Rific 
Barrel  Company,  of  New  Haven,  Conn.  Barrels  made  by  this  company 
are  stain  peu  AV  at  rhe  muzzle. 

In  the  137  accidents  here  imported  uik  burnt  barrels  were  the  cause 
in  the  guns  having  the  following  serial  numbm: 

Springfield  Armory  .Make  Rock  Island  Arsenal  Make 

Nos. 

523,089  None 

52I1444 

759.943 

902,871 

1,004,623 

1,137,620 

1,145,956 

1,201,472 

1,226,267 

1,254,701 


AGCU»ENTS  RESULTING  IN  DAMAGED  REC£(VERS 


Rifle  No. 


656701 

31224^ 

Unknown 


RIA1131J5 

48M40 

89728 

UnknownCj) 
89720 
RLV 108448 
RIAi  17794 
UIA445T36 

RIA25324I 

RIAi62i6) 

RIA2409I4 

RIA21.J754 

RIA239356 

RIA225764 

RtAi65282 
200512 
7 '2363 
501719 
666263 
661284 
RIA203851 
RLAioiioo 
Unknown 
RIA177232 


Receiver 


Persons  Lijured 


7/16/1917 

7/20/1917 

9/19/1917 

10/8/1917 

19T7 

9/18/1917 

1917 

T9T7 

1917 

8/1917 

12/19*7 

1/17/1918 

1918 
1918 
1918 
1918 
1918 
1918 
1918 
1918 

6^1918 

5/1918 

j/20/18 

2/20/19 

2/22/19 
2/ 26/20 
5/13/20 
10/24/21 
3/192J 


Heat 

Treatment 


Old* 

Old 


•^■pe  of 
r allure 


Fractured 


Shacrcrcd 


Fractured 


Broke 


Fra^ttited 

Slutrered 

Fractured 

Burst 


Shattered 

Fractured 

Faded 

Shattered 


Failed 

Shattered 

U 

Fractured 


Extent  of 
Injury 

“slight 

Severe 

Sliglit 

Slight 

Slight 

Slight 


Slight 


Slight 


Not  Serious 


Loss  of  Right  Eye 
Loss  of  Left  Eve 

Slight 


Hatcher's  Notebook 


RI\i4dt84 

9/16/:: 

Old 

Shancxed 

t 

Sl^ht 

946508 

1923 

New 

Deformed 

RIA234466 

19:3 

Old 

Shattered 

RIAJ3574J 

19*3 

44 

44 

625587 

1924 

xt 

Failed 

0 

RIA 

6/1924 

i 

Shattered 

1 

Slight 

RIAa5056o 

to/i7/»3 

i " 

44 

1 

M 

284086 

7/11/13 

' u 

1 

44 

I 

44 

64:742 

5/9/»3 

1 « 

Fractured 

1 

Loss  of  Right  Eye 

RIAio49a6 

4/30/23 

4« 

1 

Shattered 

I 

Serious 

Unknown  ! 

5/«9»4 

u 

Ruptured 

I 

Slight 

n8na 

<3/25/14 

H 

1 

Fractured 

0 

642675 

14 

Shattered 

1 

Serious 

468300 

2/6/25 

« 

Shattered 

2 

19508: 

3/4/M 

u 

44 

4 

Slight 

106332 

4/24/15 

u 

44 

RIA  170^5 

6/5/15 

u 

Fractured 

i 

Slight 

RIA1465S4 

6/10/25 

u 

Shattered 

1 

Slight 

2V945" 

rt/27/25 

a 

a 

1 

Severe 

RIAindai 

7/1/16 

f 

Fractured 

2 

1 Severe,  j Slight 

84685 

4/13/26 

II 

Sliarrered 

1 

Slight 

173807 

8/15/26 

H 

Fractured 

1 

Severe 

RLA:o48oi 

10/21/26 

41 

Shattered 

1 

Serious 

UnknoNvn 

9/11/26 

M 

44 

1 

Slight 

43076 

8/19/26 

44 

II 

1 

Slight 

560852 

7/13/17 

44 

e4 

0 

^34479 

2/3/28 

( m 

l4 

1 

Slight 

59^1480 

8/19:8 

44 

Fractured 

u 

2J550I 

4/21/29 

14 

Shattered 

0 

9517x8 

5/8/19 

<1 

Bulged 

1 

Slight 

7*3675 

19:9 

New 

Shattered 

1 

Slight 

*74*7* 

1929 

Shattered 

1 

Slight 

7'«255 

8/17/29 

H 

Shattered 

1 

Slight 

RIA  73153 

6/9/29 

M 

Fractured 

I 

801548 

1929 

4i 

Shattered 

0 

•Evidently  this  number,  indicating  a receiver  with  the  new  heat  treatnient,  is  wmng.  as  the  accidenT  happened  in  1918,  while 
Rock  Island  Ueceiver  No.  44513d  was  not  made  until  May  i9i9> 


RprORD  OF  AcaoRNTS 


Hatch fr's  Noteikjok 


44S 

July  16,  1917. 

Rrfie  No.  fi5d70j 

l\e)ercnce:  R 474.1/105 

Locariom  Works  of  the  Nmi«io:il  Brass  & Cnp|»cr  Tube  Co.,  Inc.,  Hastings-on- 
thc -Hudson,  N.  Y. 

Orgattization: 

Persons  Injured:  One.  Operator  sli^tly  scratched,  bniiscd  and  ivcorcd. 

Po'wder:  Hercules  K pyro  D G lot  446  from  Frankford  Arsenal, 

Nature  of  failure:  Splinters  were  broken  from  the  edge  0/  che  bole  and  the 
whole  bole  core  back  thru  the  pieces  of  the  housing,  including  the  cutoff 
and  ejector.  These  were  recovered.  The  smaller  bits  went  thru  the  roof  and 
window  into  the  river.  The  face  of  the  e|cctor  was  dented  and  fused  and 
highly  polished,  on  the  extreme  end.  The  barrel  and  bore  were  intact,  the 
empty  case  from  the  clip  cannelure  foru’ird,  remained  in  tlic  chamber.  The 
bolt  cue  che  whole  receiver  housing  dearly  away  on  cop  and  the  gas  opened 
the  bottom  of  the  m^azine  and  ripped  the  wunut  stock  away  on  the  left 
side.  The  line  of  derjage  tm  thru  the  vent  hole  in  the  extractor  chamber 
at  the  right  of  the  rear  end  of  the  bttrrel  and  thru  the  pin  bole  directly 
helorjj  the  ejector.  Very  dwerse  steel  stniccure  was  apparent  on  every  broken 
edge.  This  rifle  had  only  fired  rounds  in  all  and  only  38  since  it  had 
last  hren  “dojwd"*  with  a solution  to  remove  fouluig. 

Note:  Rifle  burst  while  in  use  for  proof  of  .30  cal.  hall  cartridges.  (Ex- 
tracted from  repon:  Mihuiittcd  by  .Mr.  L.  D.  Van  Akcn,  Supt.  Naiianal 
Brass  & Copper  Tube  Co.»  Inc.) 

Probable  Cause:  It  is  the  jndgmem  of  every  one  wK<»  hax  «een  the  brolten  edgeK 
of  the  receiver  housing  that  the  steel  is  most  emphatically  not  properly  case 
hardened  as  per  spec  iftr  at  ions,  thar  it  has  been  heated  too  Imr  before  quench* 
ing  and  that  it  is  prone  to  burst  along  the  line  of  the  vent  and  pin  holes. 

(Lawrence  R.  Wiral,  Asst.  Inspector  Ordnance) 

The  materiel  used  appears  unrefined,  chotigh  it  apparently  v*as  hcac  treated, 
probably  case  hardened,  Ihjc  in  the  last  hating  it  was  overheated,  creating 
crysta  Hi  ration.  This  resulted  in  the  greatest  weakness  and  there  is  no  wonder 
that  it  burst. 

(Mr,  Arthur  Dnvid»oii.  Ptesidetn,  Tlw  Fairley  Davidson  Steel  Co.  Inc.) 
It  is  the  opinion  of  this  Armory  chat  the  bursts  reported  are  primarily  due 
CO  the  causes  indicated  in  this  paragraph  (cartridge  cases  nor  ^ to  standard) 
and  secondarily,  to  receivers  somewhat  bdow  the  standard.  (The  SprlngBeld 
Armory  R^ort) 

Disposition  of  Rifle:  Shipped  to  the  Springfield  Armory. 


July  20,  1917. 

Ripe  No.  312249 

Reference:  B 474.1/105 

Location:  Works  of  the  Nati<»ial  Brass  & Copper  Tube  Co.,  Inc..  Hasdng$-on- 
che-Hudson,  N.  Y. 

Organhationi 

Persons  Injured:  One.  A piece  of  the  receiver  housing  flew  back  and  struck 
George  Deal,  the  operator,  in  the  breast  piercing  his  lung  but  not  lodging 
inside. 

Povsder:  Hercules  X pyro  D G Lot  446  from  Frankford  Arscnal- 

Nature  of  Failttre:  Rifle  burst  in  a stripping  test.  The  bole  held  locked  in  place. 
The  edges  of  the  bole  face  chipped  away  just  like  in  che  Arse  rifle  (656701) 
but  the  excraccor  was  blown  off  and  the  ejector  was  not  deformed.  AU  of  che 
housing  except  that  piece  which  engages  the  bolt  lug,  was  blown  away. 
The  barrel,  chamber,  and  bore  were  not  injured  and  all  the  case  except 
the  head  remained  in  the  chamber  )usr  as  in  the  other  rifle  (656701).  The 


Record  of  Accideki^^ 


449 

line  of  break  ran  thru  the  extractor  chamber  vent  and  thru  ibs  pin  hole 
beneath  the  ejector ^ just  beside  the  magazine  cutoff.  The  rifle  was  blown 
clear  apart.  The  only  reason  more  harm  was  not  done  is  that  the  rifle  was 
mounted  on  a sliding  rest,  and  when  fired  all  of  it.  from  the  magazine 
forward,  was  sticking  thru  a port  oat  idto  the  gallery.  The  piece  which 
injured  the  operator  came  back  thru  this  part,  the  h^irrcl  group  fell  outside 
ill  die  gallery.  This  rifle  >12249  flred  H26  rounds  in  all.  Jc  burst  on  the 
1471)1  round  of  a stripping  test.  I personnlJv  saw  chat  ic  was  natcr  cooled 
and  cleaned  every  fifty  sliots  and  was  right  beside  the  operator  during  the 
tesc.  ihere  was  no  muffled  or  dull  explosion.  Every  shot  kicked  up  dust  in 
the  backsh(»p.  (Extracted  from  nrpiHt  of  i.aurence  R.  \Mrsil,  .Asst.  Inspector 
Ordnance). 

\*robable  Cause:  Same  as  for  Rifle  65670  (. 

tYtsposition  of  Rifle:  Shipped  to  the  Springfield  Armory. 


Sept.  19.  J917. 

Rille  No.  Not  known. 

References  R474.r/i45 

Location:  Training  Omp.  Receiving  Ship,  Philadelphia,  Pa. 

Organizationt  U.  S.  Navy*. 

Persons  hjisred:  One.  Burrill  Robinson.  Gunners  Mate,  jst  Cl.  U.  S.  Navy. 
Slightly  injured  about  forehead  and  face. 

Anmrunition:  Model  1916  Ball  camidges,  stamped  6*17.  Manufactured  by  Hastings • 
on-the*Hudson  (AB,  Ac  C.T.  Co.)  lot  #j6-j9»4t. 

Nattsre  of  Faihtre:  The  breech  of  the  rifle  exploded.  Rifle  was  completely 
shattered  around  the  bolt.  (Report  of  E.  F.  Leiper,  U.  S.  N.  Tlie  Receiving 
Ship  at  Philadelphia.  Pa.) 

Probable  Cause:  See  Report  of  the  Springfield  Armory,  following*- 

Disposition  of  Rifle:  ForsvarJed  to  the  l^reau  of  Ordnance,  U.  S.  Navy  (Tile 
No.  5204*2  (8009)  9/19/1927,  and  later  carried  with  four  other  rules  rn  The 
Springfield  Armor>»  by  Ucut.  J.  A.  Patch,  O.  O.  R.  C. 


Oct.  8,  1017. 

Rifle  No.  Not  known. 

Reference:  R474.r/i46 

Location:  Navy  Klfle  Rnnge,  Virginia  Beacli,  V'a. 

Organization:  Company  47,  Receiving  Ship,  VSS.  Richmond,  U.  S.  N. 

Persons  injured:  One.  Apprrntice  Seaman,  R.  R.  Green,  above  organization, 
received  a frapnenc  of  brass  in  the  nose  and  his  face  was  pined  with  p<iwdcr 
and  badly  bruised.  Report  of  the  sui^on  in  cha^e  showed  that  he  was  not 
seriously  Injured. 

Airnmimtion:  Manufactured  by  National  Brass  & Copper  Tube  Co.,  Inc., 
Cartridges  bore  the  dates  of  May,  June  and  Jolv  1917. 

Natttre  of  Failure:  Blew  off  the  t<^  of  the  receiver,  the  maqazine  cut-off  and 
the  bridge  of  the  receiver.  Also  the  head  of  the  cartridge  was  blown  off 
and  the  stock  of  the  rifle  split  from  the  rear  sight  to  the  grip.  After  the 
explosion  the  bolt  was  in  place,  fully  pulled  d««wn  in  the  correct  position 
for  firing.  (Report,  J.  R.  Hayden,  17.  S.  N.) 

Probable  Cause:  See  report  of  the  Springfield  Armory  following— 

Disposition  of  Rifle:  Delivered  to  the  Springfield  Armory  with  four  ocher  rifles 
by  Lieut.  J-  A.  Patch,  O.  O.  R.  C. 


IIatcukr's  Notebook 


450 

Oct.  8,  1917. 

liifie  No.  Not  known. 

Reference:  R474.1/146 

Location:  Navy  Rifle  Range,  Virginia  Beach,  Va. 

Orgitnization:  U.  S.  Navy, 

Persons  fnjiered:  One.  The  piece  was  fired  by  J.  F.  Gooch,  S ic,  coach,  who 
had  fired  once  immediately  before  die  explosion  to  test  the  rifle,  the  man 
under  instruction  having  made  ten  consecutive  misses.  Gooch  received 
several  small  pieces  of  debris  in  die  i^it  eye  ball  and  his  face,  nose  and 
forehead  were  peppered  with  powder  and  small  panicles  of  steel.  One 
small  piece  also  penetrated  his  left  eye.  The  report  of  the  surgeon  in  cha^e 
seated  the  man  was  not  seriously'  injured. 

Ammurdtion'.  Maziufactared  by  Naoonal  Brass  & Copper  Tube  Co. 

Nature  of  Failure:  The  piece  was  completely  wreck^.  The  stock  was  shattered 
from  the  forward  pare  of  the  rear  sight  to  the  gr^?,  so  that  the  rifle  is  in 
two  parts.  The  receiver  was  broken  entirely  in  two  at  the  forward  and 
where  the  barrel  screws  into  it.  The  bolt  was  blown  off  but  not  injured 
except  for  a few  fragments  torn  from  the  face.  The  right  side  of  the  cut- 
off was  broken  off  and  the  right  side  of  the  receiver  was  picked  up  117  feet 
distant.  (Report  of  J.  R.  Hayden,  U.  S.  N.) 

Probable  Cause:  See  reparc  of  die  Springfield  Armory  following, 

Disposition  of  Rifle:  Delivered  to  the  Springfield  Armory  with  four  other  rifles 
by  Lieut.  J.  A.  Parch,  0.0.  R.  C. 


Dace  — 1917. 

Hlfle  No.  Not  known. 

Reference:  R474.1/147 

Location:  Navy  Rifle  Range.  Virginia  Beach.  Va. 

Organization:  U,  S,  Navy. 

Record  not  clear— Above  file  refers  ro  reptirt^  coverum  the  bursting  (»f  five  rifles, 
three  of  which  have  been  previously  covered.  Reference  R474.X/145,  146. 


Date  •“  1917. 

Rifie  No,  Not  known. 

Reference:  R474.1/147 

Location:  Navy  Rifle  Range,  Virginia  Beach,  Va. 

Organization:  u.  S.  Navy. 

Record  not  dear— Above  file  refers  to  reports  covering  the  bursting  of  five  rifles, 
three  of  which  have  been  previously  covered,  Reference  R474.1/145,  146. 

Concerning  five  rifles  the  Springfield  Armory  Reports  as  follows:  (1^474,1/(48) 

1.  Returned  with  the  information  that  the  five  rifles  delivered  at  this 
Armory  by  Licuc.  J.  A.  Patch  have  been  carefully  examined  with  the  result 
that  nothing  detrimental  in  the  nature  of  the  struettzre  of  the  metal  has 
been  disexivered  which  miglic  be  a source  of  the  bursts.  In  one  case,  an 
examination  of  the  metal  of  one  of  the  receivers  indicated  that  the  heat 
treatment  was  slightly  under  nonnal  but  not  to  any  degree  which  would 
be  conductive  to  weakening  the  metal  so  (hat  it  would  not  withstand  the 
required  pressure. 

2.  An  examination  has  also  been  made  of  the  cartridge  cases  taken  from 
the  rifles  which  were  in  use  at  the  time  the  rifles  burst.  Microscopic  photo- 
graphs of  the  brass  used  in  die  manufacture  of  these  cartridge  cases  are 
inclosed  herewith  together  with  the  photograph  of  a case  manufactured  at 
Frankford  Arsenal.  A comparison  of  these  photographs  will  indicate  a large 
grain  structure  of  the  Natiooal  Brass  & Copper  Company’s  case  which  is 
evidently  produced  through  annealing  the  case  'wldiout  a final  mechanical 


RrCORD  of  AcrJDENTS 


45* 

drawing  co  w*ork  out  the  Urge  grain  scniccuFe.  The  cases  are  therefore 
nmcerinlly  weakened  and  softened  and  k is  thought  that  undoubtedly  the 
explosions  which  occurred  were  directly  due  co  ammunition  and  in  no 
way  chargeable  to  the  metal  used  in  the  rides. 

Three  of  the  five  preceding  rifles  covered,  whicfi  failed  during  Navy 
target  practice  were  ft>rwardcd  froju  the  Springfield  Amvin’  ro  rhe  \^■acc^- 
town  Arsenal  for  meuUurgical  report  on  tlu  steel  used  in  these  rifles 
(R-474.1/19&).  The  following  k extracted  from  F.xpcrimcntal  Report  #86 
submitted  by  the  Watertown  Arsenal: 

‘^Thc  receiver  on  one  of  these  rifles  was  not  broken.  One  was  numbered 
547854.  Two  had  receivers  so  badly  broken  cite  numbers  could  not  be 
obtained.  No  cartridge  fragiiKnts  were  found  in  any  of  these  rifles.  Portions 
of  the  receivers  of  two  of  the  rifles  have  heeii  examined.  The  material  is 
exceedingly  brittle  and  the  composicioa  is  far  from  what  would  be  con> 
sidered  desirable.  Microscopic  examination  showed  diat  ilic  siee)  of  the 
receivers  was  very  streaky,  and  the  structure  was  such  as  would  Indicate 
tliat  the  material  had  not  been  properly  licar  treated  subsecpicm  to  tlic 
case-hardening  operation.  The  receivers  were  so  hard  that  it  was  necessary 
to  anneal  them  before  raking  out  samples  fur  chemical  analysis.  Sulphur 
and  Pliosphorus  exceeded  the  allowed  limits.  (Signed— K.  C.  Langenbcrgi 
jMewllurgut)” 


Sept.  18,  1917. 

Rifle  No.  RIA  **3235* 

Reference:  R 474.1/149. 

Location:  Winchester  Repeating  Arms  Co.,  New  Haven.  Conn. 

Organization: 

Persons  Injured:  One.  Operator  was  slightly  cut  about  the  face. 

Ammnition:  W.  R.  A.  Co.  lot  #ro,  Powder  lot  #486. 

Nature  of  Failure:  Receiver  forging  was  shattered  into  six  pieces,  these  pieces 
being  driven  from  the  gun  with  considerable  force.  The  majority  of  the 
cartridge  cases  remained  in  the  gun  and  the  b<»lc  was  intact  except  for  a 
small  ^acturc  on  the  face.  Previous  to  the  explosion  rifle  barrel  had  been 
flred  4242  times.  Number  of  shots  fired  with  the  receiver  may  liave  been 
three  or  four  times  this  number  (Report  of  F.  E.  Hadley,  isc  Lieut.  Ord. 
Dept.  U.  S.  R.,  Inspector  at  the  W.  R.  A.  Co*s.  plant,  New  Haven,  Conn.) 

Probable  Csatse:  In  accordance  with  instractions  given  in  the  loth  Ind.  R.  I.  A. 
receiver  No.  223235  was  received  attached  to  a rifle  barrel  made  by  the 
Winchester  Arms  Cxnnpany.  A careful  examination  reveals  the  fact  that 
the  receiver  appears  to  contain  an  old  crack  in  the  right  hand  wall,  which 
was  evidently  there  before  the  exploskui.  Varloos  slight  hairline  cracks 
appear  in  the  front  end  and  right  side  of  the  receiver,  but  it  cannot  be 
definitely  stated  whether  or  not  these  were  in  die  receiver  before  the 
explosion.  The  fracture  indicates  a good  cough  structure,  which  is  borne 
out  by  the  fact  that  the  entire  receiver  •tnas  not  shattered.  Since  the  de- 
stroyed portion  is  that  which  overhangs  the  bolt  end  of  rhe  barrel  after 
assembling,  indications  are  chat  there  was  a blow-back,  and  if  the  receiver 
had  been  excepdonallv  hard  or  overheated  in  manufacture,  it  would  have 
been  blown  entirely  from  the  barrel.  (Report  of  the  Rock  Island  Arsenal.) 

Disposition  of  Rifle:  Shipped  to  the  Rock  Island  Arsenal. 


452 


Hatchkr’s  Nqikbook 


Date  1917. 

Rifies  Nos.  ^966^ 

89728 

5 numbers— No  record. 

References:  E S 474.1/3 

Loettiion:  Record  indkaecs  four  were  from  the  Navy  and  one  from  Fort  D.  A. 
Russel  L VV'‘yoming. 

Ofganh^tion:  No  record  other  than  above. 

Fersons  Injured:  No  record. 

Anrmunition:  No  record. 

Nature  of  Failure:  RcceiveTs  broke  (Record  of  Failure.  Accidents  Malfunctions. 
Library  File,  No.  OKU-4oo^3.2> 

Vrobable  Cause:  Defecrivc  heat  treatment  (Record  of  Failures,  accidents,  Mal- 
functions, Library  File,  No.  OKD^4oo43a) 

Disposition  of  Rifiest  No  record. 

(Note:  No  further  information  could  be  olitained  from  ilic  aUnve  qunred 
file  reference.) 


Date — , 1917. 

Rifle  No.  573014. 

Reference:  0.  O,  474.1/186 

Location:  Great  Lakes  Naval  Training  Station. 

Organization:  U.  S.  Navy. 

Fertons  Injured:  One.  Fircr  slightly  injured. 

Atmnunhion:  Lot  #402,  Frankford  Arsenal,  .Manufactured,  April  14,  1917. 
Nature  of  Failttre:  Bolts  and  lugs  stripped,  bending  and  damaging  magazine. 
Probable  Causes.  Ammunition. 

Disposition  of  Hific.  No  record. 


Dare—,  1917. 

Rifle  No.  573697 

Reference:  O.  O.  474.1/186 

Location:  Great  Lakes  Naval  Training  Station. 

Organization:  U.  S.  Navy. 

Fersons  Injured:  One.  Fircr  severty  injured  b the  face. 

Avrrmmition:  Lot  #402,  Frankfnrd  Arsenal,  Manufactured  April  14,  1917. 
Nature  of  Failure:  Bolt  and  lugs  stripped,  magazine  beiu  an<l  stock  broken. 
Probable  Cause:  A mm  11  n Won. 

Disposition  of  Rifle:  No  record. 


Date — , ipty. 

Rifle  No.  632817 

Reference:  O.  O.  474.1/186 

Location:  Great  Lakes  Naval  Training  Station. 

Organization:  U.  S.  Navy. 

Persvns  Injured:  One,  Firer  slightly  injured. 

Arrmtunition:  Lot  #407,  Fiankforrf  .Arsenal,  Manufactured  April  14,  1917. 
Nature  of  Failure:  Bolt  lugs  stripped,  magazine  bent  and  stock  broken. 
Probable  Cause:  ArTmmnriinn. 

Disposition  of  Rifle:  No  record. 


Record  of  Acccdekts 


453 


August,  1917. 

Rifle  1^0.  89720 

Reference:  R 474.1/177 

Location:  Fon  D.  A.  Rassdl,  Wyoming. 

Organization:  Tnxjp  ist  Cavalry. 

Perio/w  Injured:  ^0  record. 

Ammunition:  No  record. 

Nature  of  Failure:  Explosion  separated  the  barrel  /rom  ilie  receiver,  completely 
destroying  the  latter  but  apparently  leaving  the  barrel  uninjured. 

Probable  Cause:  No  record.  (No  details  obtainable.  Record  of  Failures,  Ac- 
cidents, Malfunctions,  Library  File  No.  OKD  400.43.!  > 

Disposition  of  Rifle:  Shipped  to  tlie  ofBce,  Chief  of  Ordnance. 


August,  1917. 

Rifle  No.  No  Rccijrd 
Reference:  R 474.1/84 

Location:  Culver  Mllitar)  Academy,  Culver,  Ind. 

Organization:  No  record. 

Persons  Injured:  No  record. 

Ammunition:  No  record. 

Nature  of  Failure:  Exploded  on  rifle  range. 

Probable  Cause:  No  record. 

Disposition  of  Rifle:  No  record.  . 


December,  1917. 

Rifle  No.  RIA  108448 
R^erence:  R 474.1/13 
Location:  Camp  Shelby,  Miss. 

Organhaiion:  170th  Infantry. 

Persons  Injured: 

Amrmtnition:  U.  S.  Cartridge  Co.,  marked  ‘’17”. 

Natme  of  Failure:  The  barrel  was  burst  at  the  chamber  and  split  over  one- 
third  of  the  distance  to  the  mu22le. 

The  portion  of  the  receiver  into  which  the  barrel  screws  was  shattered  as 
far  back  as  the  forward  end  of  the  bolt. 

(Col.  Chas.  E.  Morrbon) 

Probable  Cause:  Defective  material  composing  the  barrel.  High  SLilphur  and 
phosphorus  content  (Watertown  Arsenal,  Report  signed  by  F.  C,  Langen- 
bert,  Metallurgist). 

Disposition  of  Rifle:  Ship|)«d  to  the  Watertown  Arsenal. 


January  17,  19(8. 

Rifle  No.  RIA  1^7794 

Reference:  E S 4744/90,215,228 

Location:  U.  S.  Rifle  Range,  Mount  Holly,  N.  C 

Organization:  Co.  “C”  10th  U.  S.  Infantry. 

Perstms  Inptred:  One-  Corp.  Floyd  P.  Whiting,  above  organiweion,  the  firer 
was  slightly  injured. 

Ammunition:  No  record. 

Nature  of  Failure:  Receiver  buret  away  from  the  barrel. 

Probable  Cause: 

a.  The  dcfeccrve  rifles  have  been  examined  in  this  ofiice  (O.  C.  of  O.) 
and  the  reason  for  rifle  217794  bursting  at  the  receiver  is  in  all  probability 


454 


Hatcubr's  Notebook 


in  accurdauce  with  dte  fauts  as  snti^A  in  report  artauhed  hereto.  The  £ring 
pin  rod  was  evidentJy  broken  and  allowed  the  striker  point  to  project 
thru  the  firing  pin  hole  nf  the  bole.  Therefore,  when  the  bolr  was  thrown 
smartly  forward,  thus  allowing  the  striker  point  to  come  in  contact  with 
the  cartridge  primer  before  the  cartridge  reached  irs  position  in  the  chamber, 
a premature  explosion  occurred,  causing  the  rupture  of  the  receiver.  (Captain 
R.  R.  Higgins,  O.  R.  C office  of  C.  of  O.) 

b.  The  receiver  of  this  rifle  had  not  been  pro|>erly  heat  treated  prior 
to  being  put  in  service, 

The  metal  was  very  brittle  under  impact,  as  evidenced  by  its  being  readily 
broken  when  struck  a light  blow  with  a hammer.  (£jtp.  Report  #215, 
Watertown  Arsenal,  signed  by  F.  C.  Langenberg,  Metallurgist,  May  id,  1918), 
Disposition  of  Rifle:  Shipped  to  the  Watertown  Arsenal. 


February,  1918. 

Rifie  No,  nail 

Reference:  E S 474.4/108 

Location:  Camp  Shelby,  Miss. 

Organization:  Battery  “E”,  1J9  F.  A. 

Persons  Injured:  Prv.  Edward  Copeland,  the  firer,  slightly  injured. 

Anrmunition:  Lot  8a  of  lot  453  of  1817,  Manufactured  by  the  Western  Cartridge 
Co. 

Nature  of  Failure:  Shell  case  was  jammed  fast  in  chamber.  Portion  of  rim 
near  lower  lug  was  split  off.  Pan  uf  upper  lug  was  broken  off.  Extractor 
collar  ear  broken  oif.  £.\tractor  tongue  was  broken  in  two,  about  one  half 
inch  from  gas  outlet.  From  point  of  break  the  tongue  was  bent  about 
ewen^  degrees.  Magazine  was  warped  on  right  side  and  stock  was  split  on 
left  Side.  Sleeve  was  broken  off  and  magazine  floor  plate  was  bent.  Small 
bits  of  brass  were  found  and  that  part  of  the  head  of  the  shell  case  ap* 
patently  contained  * 'rotten  brass**  covered  bv  a thin  outer  coating.  (Record 
of  Proceedings,  Board  of  Inquiry.  Camp  Sficlbv,  Miss.  February  :8,  1918) 

Probable  Catsse:  Defeccfve  ammunition. 

Disposition  of  Rifle:  No  record. 


Rifle  No. 


Date—,  1918. 


RLA  445136 

Nature  of  Faiiitre 
Burst  Receiver 

SA  278671 

Back  Fired 

s s 

RIA  253241 

Burst  Receiver 

RIA  262165 

Burst  Receiver 

RIA  240914 

Burst  Receiver 

RIA  239754 

Burst  Receiver 

RIA  239356 

Burst  Receiver 

RIA  225764 

Burst  Receiver 

RIA  3J45J4 

Back  Fired 

RIA  165282 

Burst  Receiver 

Reference:  E S 474.i/:83 
Location:  Camp  Cody,  K.  M. 

Organization:  No  record. 

Persons  Injured:  No  record. 

Ammunition:  Winchester,  lots  A-IJ7  and  AO121,  E S 474.1/141. 

Probable  Cctuse:  (Report  of  the  Springfield  Amitiry,  January  23,  1919,  File 
E S 474,i/2i<3) 

1.  The  rifles  mentioned  above  hare  been  examined  and  the  primary  cause 
of  failure  w-as  evidently  due  to  faulty  ammunition,  and  in  every  instance, 
the  shells  rerumed  with  these  rifles  have  heads  blowm  off. 


RilUORD  of  Acciof.vts 


455 

2.  Th«  condition  of  the  receiver  seed  also  concributed  to  faQure.  Sufficient 
material  could  be  identified  for  ansilyas  of  &iz  receivers.  Three  of  these 
showed  abnormal  analysis  that  would  be  cause  for  rejecting  raw  stock  as 
follows; 

RIA  2^9754  Sulphur  .o6H  Pho^horus  .068 

RIA  240914  Sulphur  .131  Phosphorus  a>^6 

RIA  44513d  Sulphur  .093  Phosphorus  .114 

One  receiver  (SA 165 282)  showed  slightly  dirty  steel  as  indicated  by  slag 
incliixions  i>l>servcd  in  the  unctchcd  niculli^raphic  specimen. 

(a)  The  mccallographic  stmeture  of  dicse  receivers  (Fig.  1,  2,  3)  is 
not  uniform  nor  dors  it  conform  Co  the  structure  obtained  in  our 
present  practice  (Figs.  4 and  5).  Fig.  1 shows  islands  0/  free  ferrite, 
the  restulrs  of  an  mefltctivc  (jiiench  (rifles  239854  and  2409  j 4).  Hg.  2 
is  the  structure  of  an  unhardened  receiver,  or  one  hardened  at  much  coo 
low'  a heat  (Rifles  353241  and  445136.)  Fig.  3,  (Rifle  165282)  is  not 
onl>  unhardened  but  the  gram  is  very  coarse  as  from  high  foiging 
heac 

3.  Rifle  278671  is  a cleaned  and  repaired  arm,  the  receiver  being  of  Spring- 
field  manufacture  assembled  to  a 1917  RL\  barrel. 

4.  The  back  firing  on  rifles  2 245 >4  278671— these  appeared  to  have 

been  fired  with  cartridges  having  excessive  pressure,  die  nm  of  the  bolt 
being  blown  off  and  rne  canriugc  cases  showing  evidence  of  this  high 
pressure.  (Springfield  Armory) 

!)hpO!iti^  of  Rifles:  Fonvarded  to  rhe  S|)ringfield  Armory. 


June,  19(8. 

Kifie  No.  658742 

R^trrefioe:  F.  S 474.1/151 

Location:  Plant  of  Remiogton  U.  M-  C.  Company,  Bridgeport,  Conn. 

Organizatirm: 

Fersons  Injured:  No  record. 

Antnrtmition:  Remingttin  U.  S.  M,  Co. 

Nature  of  Failure:  Rifle  burst  about  two  inches  from  the  muule.  Burst  while 
firing  stripping  test.  Rifle  had  fired  10890  rounds. 

Frobablc  Cause:  R is  the  conclusion  of  this  laboratory  that  the  metal  used  in 
the  manufacture  of  this  rifle  barrel  was  very  undesirable  material  for  this 
purpose.  The  metal  contained  numerous  long  slag  Inclusions.  Phosphorus 
segregation  was  revealed  by  etching  with  Steads  reagent.  Cliemical  analysis 
showed  the  phosphorus  content  of  the  barrel  to  be  .0H8  which  is  above 
specifications  and  entirely  too  high.  (The  Watertown  Arsenal,  Report) 

Dhpimtion  of  Rifle:  Shipped  to  the  Watertenvn  Arsenal. 


June,  (918. 

Rifle  No.  200512 

Reference:  E S 474.1/126 

Location:  Camp  Shelby,  Miss. 

Organization:  Co.  “D”  n3th  Ammunition  Train. 

Persons  Injured:  Prv.  Charles  Berry,  the  firer,  sl^Uil)  iujured. 

.Ammunition:  Lot  #86,  RA-17. 

Nature  of  Failure:  Stock  split  imdemeath  from  the  magazine  tu  upper  baud, 
floor  plate  catch  broken,  receiver  broken  in  several  pieces ^ bolt  broken  into 
four  pieces,  bolt  stop  spring  misfflaced  and  the  cartridge  is  so  jammed  In 
the  chamber  tlut  the  barrel  will  have  to  be  taken  down  to  make  further 
InvescigatioD.  C Mai  or  Thompson  Short,  In/.,  N.  C.) 

Prnhfihle  Cattse:  No  record. 

Disposition  of  Rifle:  No  record. 


456 


Ha'icher’s  Notebook 


Kifie  No.  S A 723664 
Reference:  E S 474.1/107 
Locati<yn:  Camp  Wheels,  Ga. 
Organhation:  Co.  “D”  izi  Inf. 

Refiom  Injured:  No  record. 
Arrtmunhion:  No  record. 

Nature  of  Failure:  Barrel  split  its  entire 

O.  R.  0 

Probable  Cause:  No  record. 

Dispotition  of  Rifle:  No  record. 


May,  191 S. 


icDgih.  (Report  Major.  Wm.  G.  Obear, 


May,  1918. 

Rifle  No.  S A 7 1 1363 
Reference:  E S 474.1/ 107 
Location:  Camp  Wheeler,  Ga. 

Organization:  (JO.  “M”  mnd  Inf. 

Perronj  Injured:  One.  Slightly. 

Ammunition:  No  record. 

Nature  of  Failure:  Head  of  shell  blew  out,  tearing  off  sides  of  receiver 
leaving  remainder  of  shell  in  barrel.  (Report.  Major  Wm.  G.  Obear, 
O.  R.  C) 

Disposition  of  Rifle:  No  record. 


March,  1918. 

Rifle  No.  S A 141157 
Reference:  E S 474.1/58 
Location:  Camp  Bowie,  Texas. 

Organhattori:  urth  Trench  Mortar  Bsctery. 

Persons  Injured:  None. 

Ammunition:  M1906  marked  for  target  practice  in  the  United  States  only. 
Nature  of  Failure:  Barrel  burst  from  the  muzzle  to  a point  five  inches  below  the 
stock swivel.  (Capt  Lewis  Maverick,  iiith  T.  M.  Battery.) 

Probable  Cause:  Unknown.  Accident  occumd  the  and  or  jra  shoe  on  300 
yard  range  during  rapid  lire  target  practice. 

Record  snows  rlne  had  been  cleaned  just  before  firing. 

DispoHrion  of  Rifle:  No  record. 


Date — , 191B. 

Rifle  No.  (Bolts  from  two  Rides) 

Reference:  E S 474.1/49 
Location:  Camp  Green.  N.  C 
Organization:  4th  Engineers. 

Persons  Injured: 

Ammunition: 

Nature  of  Failure:  Both  bolts  were  fractured  at  the  forward  end  where  chc\' 
come  in  contact  with  the  cartridge.  (Exp.  Rep.  ^100.  Watertown  Arsenal) 
Probable  Cause:  The  failure  of  both  of  these  bolts  is  due  to  the  same  cause. 
Both  we«  very  hard  and  brittle.  The  c.xisccncc  of  such  a srnirrnre  as  that 
found  in  the  two  bolts  is  brought  about  bv  insufficient  tempering  after  the 
quenching  operation.  (Watertown  Arsenal) 

Disposition  of  Bolts:  Shipped  to  the  Wattrtow'o  Arsenal. 


February  to.  1918, 

Rifle  No.  501719 

Reference:  F S 474.1/^4  (E  S 47141/125) 

Location:  Camp  McClellan.  Ala. 


Rrcofu>  OF  Accim;nis 


457 

Organizati<m:  112th  M.  C.  Batcdion 

Persom  Injured:  One.  (Record  of  Failures,  Accidents,  Malfunctioxis,  Libiarj' 
File  No.  O.  K.  D.  400-45.2) 

Ammunition:  No  record. 

Nature  of  Failures:  No  record. 

Probable  Cause:  Defective  receiver  and  ammunition.  (Record  same  as  quoteil 
for  Persons  Lijured) 

Disposition  of  Rffie:  No  record. 

Note:  Nn  further  infonnaiion  could  be  obtained  from  the  above  quoted 
tile  reference) 


February  10,  23,  1919- 

Rifie  Nos.  666265,  ^2284 

Reference:  MR  47141/570,  MR  474.1/57 

Location:  Lindsay  Arsenal,  Canada. 

Orga?tization: 

Persons  Injured:  One.  Not  seriously. 

Ammunition:  Lot  #L-9,  Frankford  Arsenal. 

Nature  of  Failure:  Stock  shattered  around  the  breech  mechanism.  Receiver 
broken  into  a number  of  pieces.  Bolt  head  broken  on  face  and  one  lug 
knocked  off.  Ride  failed  during  accuracy  tests  of  Armor  piercing  car- 
tridges. 

Vfohabie  Cause:  Both  rides  failed  because  chc  receivers  had  nor  been  given 
proper  heat  treatment.  The  phosphorus  and  sulphur  content  in  both  cases 
was  higher  than  desirable.  (Ex^rimental  Report  No.  157,  Watertown 
Antenal) 

Disposition  of  Ripe:  Scrapped  at  the  Watertown  Arsenal. 


April,  1920. 

RiPe  No. 

Reference:  O.  0.  474.1/4245 

Location:  Empire  City  and  Rifle  Oub,  990  Trinity  Avenue,  Bronx,  N.  V. 
Organization:  Rifle  was  property  oi  Mr.  A.  P.  Hahn. 

Persons  Injured:  No  record. 

Ammunition:  No  record. 

Nature  of  Failure:  Barrel  split  at  the  muulc  for  about  two  inches. 

Probable  Cause:  Break  in  barrel  was  believed  to  have  been  caused  by  an 
obscruccion  in  the  barrel.  (Springfield  Armory) 

Disposition  of  Ripe:  Rcoaired  and  returned  to  Mr.  Hahn  at  his  cYpense. 
(Springfield  Armory). 


July  29,  1920. 

Ripe  No.  167204 
Reference:  O,  O.  553.14/40 
Location:  Sandy  Hook,  N.  Y. 

Orgarthation:  2nd  Co. 

Persons  Injured:  No  rccord. 

Ammurnthn:  No  record. 

Nature  of  Failure:  Barrel  burst. 

Probable  Cause:  Obstruction  in  bore. 

Disposition  of  Ripe:  No  record. 


June  26,  1920. 

Ripe  No.  RIA  203851 
Reference:  47141/1172 

Location:  Veilbach  Rifle  Range,  Germany. 


Hatcher’s  Notebook 


458 

Organtzation:  Headquarters  Co.  8di  Infantry. 

Persons  Injured:  No  record. 

Aimmenitiont  U.  S.  C.  Co..  L«»ts  #715  and  698. 

Nature  of  Failure:  Floor  plate  bent  forward.  Receiver  shattered  about  the  hekmg 
chamber  at  the  forward  trud,  top  parr  completely  blown  away.  The  re- 
ceiver  was  almost  broken  m two  immediately  bemnd  the  safety  shoulder. 
The  bolt  was  brtiken  In  two  at  the  safety  lug  and  rested  at  an  angle  which 
held  the  front  end  about  one  inch  above  its  normal  position.  All  parts 
In  rear  c»f  the  chamber  were  more  or  less  coated  with  fused  brass.  Barrel 
was  uninjured.  TTw  canridge,  except  the  base  which  was  blown  oif, 
raiuined  In  the  chamber.  There  was  no  question  about  it  being  U.  S. 
Ammunition,  (ist  Lc.  W.  J.  Henry,  12th  L.  M.  O.  R-  S.) 

Probable  Cause:  Defective  ammunition.  (Lt.  Henry). 

Disposition  of  Rifle:  No  record. 


May  23,  1 920. 

Rifle  No,  RIA  lotaoo 

Reference:  O.  O.  47141/1171 

Location:  VVehr  range,  Germany. 

Organization:  Headquarters  Co.  jth  Wantry. 

Persons  Injured:  No  record. 

Arrmrunirion:  W.  R.  A.  Co.,  Lot  A- 161,  1918. 

Nature  of  Failure:  Receiver  wis  completely  demolished.  Cartridge  stuck  in 
chamber  with  base  blown  off.  Barrel  uninjured.  (Lt.  Col.  C.  A.  Schiincl- 
fenig,  Ord.  Dept.) 

Probable  Cmtse:  Defective  ammunition  as  ic  was  decided  to  call  in  viU  ainmuiil- 
fion,  Cal.  .jo,  manufactured  hy  chat  Company,  <W.  R.  A.  Co,,)  (Report 
of  Major,  }.  K.  Crain,  C.  A.  C,  Chief  Ordnance  Odiccr,  F.  In  G) 
(Also  orders  #78,  Hdqs.  A.  F.  in  G.,  Cobicnt?..  Germanv.  i June  1920) 

Dhposition  of  Rifle:  No  record. 


October  14,  1921. 

Rifle  No.  (old  receiver) 

Reference:  O.  O.  474. 1/430 j 

Location:  Sandy  Hook.  N.  J. 

OrgatiioAtion:  6ch  Company,  S.  H. 

Persons  Injured:  One.  Prv.  icj.  Tlionias  H.  Appleby,  the  firer  Seriously  in- 
jured, resulting  in  the  loss  of  the  r%ht  eye  and  laceration  of  the  face. 

Ammunition:  German,  (S|>ringf5eld  .Armorv) 

Nature  of  Failure:  Receiver  was  shattered  and  number  was  missing.  Receiver 
was  of  the  old  single  heat  treatment. 

Probable  Cause:  The  cartridge  which  caused  the  explosion  was  still  in  the 
chamber  of  the  gun,  the  head  of  the  cartridge  having  been  blown  away. 
The  body  of  the  cartridge  was  removed  from  the  chamber  and  on  being 
examined  was  found  to  be  a portion  of  a German  7.9m/m  service  cartridge 
....  The  German  bullet  is  ^>15  larger  than  our  bullet.  Nam  rally,  firing 
a caitridge  of  this  character  in  the  Springheld  rifle  would  give  rise  to 
excessive  pressure.  From  tests  that  1 (Major  J.  S.  Hatcher)  have  made 
on  this  subject,  T And  that  the  pressure  encountered  in  such  a case  b 
generally  above  75000  lbs,  per  square  inch.  . . . Tests  also  indicate  that 
the  double  heat  treated  receiver  will  not  permit  the  gun  to  burst  ui  spite 
of  the  excessive  pressure  encountered.  Ic  can.  therefore,  with  confidence  be 
stated  that  the  cause  of  the  explosion  was  the  fact  chat  in  some  way  a 


Record  of  Accidents 


459 

Germin  service  c&rcridge  was  mixed  ia  with  the  airrmtnition  being  used 
(F.  A.  Lor  #449,  1917)  in  the  tai^et  practice  and  happened  to  get  into  a 
ride  with  the  single  heat  treated  receiTcr,  which  is  not  strong  enough  to 
stand  such  strain.  (Extracted  from  report  of  Major  J.  S.  Hatcher,  Spring- 
field  Armory,  November  a8,  1921.) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


May,  192  (. 

Rifle  No,  RlA  *772 j: 

Referefice:  O.  O.  474. 1/44 to,  4450 

Location:  Clifton,  Arizona. 

Organization:  Qifton  Rifle  Club.  Clifton,  Arizona. 

Arnmunition:  Powder— DuPont,  lot  #671,  1917  shipped  from  the  Frankford 
Anenal,  March  i8,  1921.  Hand  loaded  ammunition  using  48.9  grains  of 
powder,  service  bullet. 

Persons  Injured:  One.  Mr.  W.  F.  McBraycr,  the  firer  and  Sec.  of  the  club,  was 
seriously  injured  losing  his  left  eye. 

Nature  of  Tailure:  Receiver  failed. 

Prebahh  Cause:  i.  (a)  Excessive  pressure. 

(li>  Failure  of  the  carmUev  head,  possibly  due  to  lamination 
or  other  defect.  Some  indications  of  a lamination  were  apparent. 

(c)  Very  poor  beat  treatment  m the  recenjer, 

2.  The  chances  arc  that  a soiiKwhat  excessive  pressure,  combined  with  a 
defective  cartridge,  allowed  the  gas  to  escape  into  the  receiver  well  and 
disrupt  the  receiver.  With  a brittle  o*  poorly  beat  treated  receiver  a 
large  escape  of  gas  in  this  niannet  will  irequendy  cause  a fracture.  With 
properly  heat  treated  parts  an  escape  of  gas  as  would  occur  from  either  an 
excessive  pressure  or  a defective  cartridge  case,  or  both,  cannot  burst  the 
receiver  or  blow  out  the  bolt.  Since  our  new  heat  treatment  was  started  tn 
1917.  there  have  been  no  cases  of  the  bursting  of  these  receivers  brougi.t  to 
the  atccncicm  of  Spriugfield  Armory  and  every  effort  that  we  have  made  to 
burst  these  receivers  in  our  experimental  department  has  failed. 

3.  The  receiver  rn  i|ucsclun  was  ou  a rifle  made  at  Rock  Island  Arsenal 
in  August  1 9 CO.  Cons^ucntly  chb  rifle  did  noc  have  die  new  heat  treat- 
ment. 


5.  In  conclusion,  it  may  be  stated  that  the  opinion  of  this  armory  is  that 
regardless  of  what  causes  such  as  defective  cartridge  cases  may  Have  con- 
tributed CO  the  failure,  the  ultimate  responsibility  for  rhe  accident  is  clue  to 
the  poor  receiver,  as  with  a good  receiver  the  accident  would  not  have 
happened.  (Extracted  from  report  of  the  Springfield  Armory) 

Dispotiticn  of  Rifle:  Forwarded  to  the  Springfield  Armorv,  and  later  returned 
to  Mr.  W.  F.  McBrayer,  Secy.  Clifton  Rifle  Club,  Clifton.  Arizona. 


Jtily,  1921. 

Rifle  No.  SA  32^222 
Reference:  0.  O.  474.1/4463 
Location:  Camp  Holabird.  Md. 

Organhation:  Co.  csi  Motor  Repair  BarraKon. 

Persons  Injured:  None 
Ammunition:  Guard  cartridge. 

Nature  of  Failure:  Receiver  shattered. 


460  Hatcher's  Notebook 

FrobabU  Cause:  The  failure  of  the  rifle  had  two  cootributing  cause»t 

First,  the  fact  that  the  receiver  through  rmproper  heat  treatment  was 
brittle  and  lacked  shock  resisting  qualities,  and 
Second,  the  improper  assembly  of  the  receiver,  bole  and  barrel. 

Such  an  accident  could  not  have  happened  had  the  heat  treacment  on  this 
rifle  been  of  the  kind  now  in  use  at  Spni^field  Armory.  (Report,  Springfield 
Armory) 

DispOtithn  of  Rifle:  Forward  to  die  Sfiringfield  Armory. 


Jnly  28,  1921. 

Rifle  No.  SA  1,215,353 

Reference:  O.  O.  474.i/4464»4472 

Location:  Fort  Niagara,  N.  Y. 

Organization:  Infantry  Rifle  Team. 

Fersons  Injured:  Major  Per  Ramcc,  Captain,  Infantry  Rifle  I'cam.  Sligfnly 
injured. 

Ammunition:  Mixed  Iocs  of  F.  A.  Ammunition,  manufactured  prior  to  1917. 

Nature  of  Failure:  On  the  dth  or  7th  shot  a Kang  fire  occurred  giving  time  for 
the  lifting  of  the  bolt  handle  in  the  act  of  excraccing  the  cartridge  when 
the  explosion  took  place,  driving  the  bolt  backward,  partly  shearing  ofl 
the  edge  of  the  cut-off  and  the  upper  half  of  the  split  locking  lug.  (Ex- 
tracted from  Report  of  Board  of  Officers). 

Frobahle  Cause:  Defective  Amniunicjon  (Report  of  the  Frankford  Arsenal.) 

Disposition  of  Rifle: 


Julv  15,  19*1. 

Rifle  No.  SA  7701^0 

Reference:  O.  O.  474.1/4468 

Location:  Camp  BiiUk  Texaii. 

Organization:  Co.  2nd  Engineers. 

Parsons  Injured:  One.  Private  Frank  Godea,  above  o^aniaation,  the  flrer  was 
slightly  injured. 

Ammunition: 

Nature  of  Failure:  Receiver  broken  iiito  a number  of  pieces.  Bolt  had  the 
small  Up  opposite  the  bottom  locking  Jug  blown  away  and  had  brass  melted 
onto  the  face,  indicating  high  pressure. 

Probable  Cause:  In  the  opinion  of  this  Armory  tl)i$  accident  w'as  due  primarily 
CO  excessive  pressure  caused  by  a foreign  substance  ou  die  forward  part 
of  the  cartridge;  and,  secondardy.  to  extremely  poor  heat  treatment  of  the 
receiver  which  was  very  hard,  briuJc  and  highly  susceptible  to  shock. 
(Extracted  from  Repon  of  the  Springfield  Armory.) 

Disposition  of  Rifle:  Forwarded  to  the  Sjtringfleld  Armojy'. 

August  S2,  1921. 

Rifle  No. 

Reference:  O.  O.  474.1/4472. 

Location:  Fort  Niagara,  N.  Y. 

Organization:  Philippine  Scout  Rifle  Team. 

Persons  Injured:  Gtae.  Sightly. 

Amrmtnition:  Frankford  Arsenal,  1921. 

Nature  of  Faiiure:  Magazine  sides  swelled  out.  Stock  was  badly  broken.  The 
magazine  floor  plate  was  blown  downward  and  the  four  cartridgef«  re- 
maining in  the  magazine  were  Iikiwn  our.  The  bolt  held  in  place  firmly 
and  securely.  Bolt  was  entirdy  workable  after  the  accident. 

Probable  Cause:  The  n.se  of  greased  ammunidon. 

Disposition  of  Rrfle: 


Record  of  Accidents 


461 


July  28,  1921. 

Rifie  So.  SA  1215355 

Reference:  O.  O.  474.1/4472 

Location:  Fort  Niagara,  N.  Y. 

Or^anhation:  Infantry  Rifle  Team. 

Persons  Ir^ered:  One.  Cape.  Alan  D.  Wamock,  slightly. 

Anemuniuon:  1921,  National  xMacch. 

iVafure  uf  Failure:  Gas  escsijwcl  thru  ilic  chaiuiel  cut  in  the  frame  near  the 
receiver  to  admit  the  left  locking  log  on  the  bolt.  It  was  tliru  this  passage 
that  the  brass  and  gas  pa»ed  peppering  my  furclicad  with  a number  of 
small  pieces.  (Cape.  Wamock) 

Frobable  Cause:  Defective  ammunition. 

Disposition  of  Rifle: 


August,  1921. 

Rifle  No.  70971 

Reference:  O.  O.  474.1/4478 

Location:  Camp  Grant.  TllinoU. 

Qrgatiizdtion:  C.  M.  T.  C. 

Persons  Injured: 

Ammunition:  Could  not  be  identified. 

Nature  of  Failure:  Fractured  receiver. 

Probable  Cause:  From  examination  made  thus  far  it  is  thought  that  the  steel 
in  tills  receiver  was  in  extremely  bad  condition  and  unsuitable  for  the 
purpose  for  which  ir  was  used.  (Rxiracicd  from  Report  of  the  Rock 
Island  Arsenal) 

In  the  opinion  of  this  oflicc.  the  direct  caiixe  of  the  damage  to  the  rifle 
was  in  soft  cartridge  head,  which  permitted  the  gas  under  high  pressure, 
rather  than  defective  material  in  the  receiver;  althonOT  the  latter  umlouhtedly 
contributed  to  the  extent  of  the  damam  done.  (Ordnance  Office,  Chief, 
Small  Arms  Division,  Major  Herbert  O’Leary). 

Disposition  of  Rifle:  Shipped  ro  the  Rock  Island  Arsenal. 


June  2,  1921. 

Rifle  No.  Oojixs 
Reference:  O.  O.  474-1/4485 
Location:  San  Juan.  P,  R. 

Organization:  Co,  65th  Inf. 

Versons  Injured: 

Ammunition:  R.  A.— 18 

Nature  of  Failure:  Barrel  burst,  caunr^  a tear  of  about  1 h iuclics  uikUt  the 
front  sight. 

Vrobahie  Cause:  Obstruction  In  bore.  (Report  of  the  Springfield  Armory.) 
Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


Date — , 1921. 

Rifle  No.  SA  608498 
Reference:  0.0.  474.1 /4384»  4595. 

Locatio'/t:  Hawaiian  DK|iaraiiciit. 

Organization:  Hawaiian  OrdnarKc  Detachment. 

Persons  Injured: 

.Ammunition:  Overhauled  locally. 

Nature  of  Failure:  Barrel  burst. 

Probable  Ceuse:  Due  to  c<witinuous  slag  streaks  ir>  barrel.  {Report,  Springfield 
.Armory.) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


4^2 


Hatcher's  Notebook 


Oi9t — • 1922. 


Rifle  Nos.  459881^  379004 
Refereftce:  O.  O.  474.1/4540 
Location'.  Fon  Crook,  Ncbi. 

Organization:  Troop  “E”  14th  Cavalry. 
i^orsons  injured: 

Arnmunmon:  R.  A.  H-iS,  Gallery  practice  cartridge,  Reloaded,  Feb.  1922. 
Nature  of  Failure:  Barrels  split. 

Probable  Cause:  Obstr\tctlona  in  the  bores. 

Disposition  of  Rifles: 

September  t6»  1922. 

Ripe  No.  RIA  146184 

Reference:  O.  O.  474.1/4602  • 

Location:  Atlanta,  Ga.  During  civic  dcfDonstradon. 

Organization:  U.  S.  Army, 

Persons  Injured:  One,  'Hic  fircr*  sl%ht)y. 

Arnmunxtiirn:  Pyro  blank  cartridges  and  combination  rifle  and  hand  grenade 
“White  Phosphorus.” 

Nature  of  Failure:  Shattered  receiver. 

Probable  Cause:  Excessive  pressure.  Receiver  not  properly  heat  aeated.  was 
too  brittle  to  be  suitable  for  this  component.  It  cannot  he  said  that  any 
receiver  would  have  held,  although  no  broken  receivers  nf  Springfield 
Armor's  late  manufacture  have  been  returned  to  this  establishment.  (Re- 
pent,  bpringfield  Armory.) 

lytsposUion  of  Rifle:  Forwarded  to  the  Springfield  Armory. 

Auguac  (6,  1922. 

Hifte  No.  759943 
Reference:  O.  O.  474.1/457  ^ 

Location:  Sea  Girt,  N.  Y. 

Organization:  H<js.  Co.,  104th  Engineers,  N.  J.  N.  <1. 

Persons  Injured:  None. 

Ammunition:  Winchester,  Lot  A-j77,  1918. 

Nature  of  Failure:  Barrel  burst,  blowing  a piece  of  steel  about  three  inches  long 
out  of  the  right  hand  ade  of  the  barrel  one  half  of  these  tliree  inches 
being  the  chamber  holding  the  cartridge.  (Extracted  from  report  of  Captain 
George  C.  BonstcUe,  Co.  “.A”  104th  Eitfinecrs.  N.  ].  N.  G.  fircr  of  the 
rifle.) 

Probable  Cause:  Barrel  contained  burnt  steel.  Tlie  faihire  of  this  barrel  is  due  tn 
weakness  that  was  produced  by  exces^e  heating  in  the  upsetting  operation. 
The  excessive  heat  caused  internal  nxidation  or  burning  of  the  metal  render- 
ing  ic  entirely  unfit  for  use  as  a rifle  barrel.  (Extracted  from  report  of 
E,  L.  Wood,  Meallufgisr,  Springfield  Armory.) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


Date — , 1923. 

Rifle  No.  946508 

Reference:  O.  O.  474.1/4574 

Location:  U.  S.  Naval  Academy.  Annapolis,  Md. 

Organization:  U.  S.  Naval  Academy  Corps  of  Midshipmen. 

Persons  Injured: 

Ammunition: 

Nature  of  Failure:  Balt  and  receiver  deformed.  Barrel  showed  no  indication 
of  bultring  or  defewmation.  (Report  of  Springffleld  Armory) 

Cause  of  Fatlnre:  FxcejBive  Pressure,  (Springfield  Armory) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


RfCOKD  of  AoCIDRNTb 


46? 

Date — , 1923. 

Rifle  Nos.  RIA  234466,  235742 

R^erence:  O.  O.  474.1 /47io»  4726,  4727,  4735 

Location:  Coalinga,  Calif. 

OrzafttMtion:  Cnalinga  RiAe  Club,  CoaJinga,  Calif. 

Persow  Injured: 

Ammumiion:  Loc  #397.  R.  A.  iS. 

Nature  of  FMere:  Receivers  shattered. 

ProhabU  Cause:  Defective  ammunitioo  (Frankford  Arsenal)  It  is  concluded  that 
the  bursting  of  each  rifle  was  due  primarily  to  failure  of  the  cartridge  head, 
tlie  cause  of  such  failure  is  not  known,  combined  with  weakness  and  brittle- 
ness of  the  receiver,  and  possiUy  a^ravated  by  excessive  pressure.  (Spring- 
field  Armory) 

Oisposition  of  Rijie:  Forwarded  to  the  Springfield  Armory. 


Date — , 19:4. 

Rifle  No.  625587 

Reference:  O,  O.  474.1/4727 

Location:  The  Frankford  Arsenal,  RuJadelphia,  Pa. 

Organksation:  This  ride  blew  up  at  the  Frankford  Arsenal  while  making  a sur- 
veillance test  of  ammunition  used  in  rides  nos.  RIA  234446  and  RIA  235742 
whicli  exploded  while  being  used  by  a civilian  rifle  team  and  arc  described 
next  above. 

Penf/ns  Injured:  None 

Awmunitipni  Lot  #397,  R.  A.  18 

Nature  <if  failure:  Receiver  failed.  Bolt  held  in  place. 

Probable  Cause:  Defective  ammunition.  (Frankford  Arsenal) 

Disposition  tif  Rvfie:  Forwarded  to  the  Springfield  Armory  by  the  Frankford 
Arsenal. 


April  23»  1923. 

Rifle  No,  97076a 
Reference:  O.  O.  474.1/4652 

Location:  U.  S.  S.  Nevada  (ai  anchor)  San  Pedro,  Calif. 

Organization:  U.  S.  Navy. 

PersoTU  Injured: 

Amwunition:  Lot  #1227,  U.  $.  Cartridge  Co.,  1918. 

Nature  of  failure:  Split  Barrel. 

Probable  Cause:  Damage  was  caused  by  a bullet  being  stuck  in  the  bore 
due  to  an  insufficient  powder  charge.  (Office  C-  uf  0.) 

Disposition  of  Rifle: 


Date  ■■ 

Rifle  No.  971779 
Reference:  O.  O.  474,1/4655 
Location:  Fort  McPherson,  Ga. 

Organization:  Co.  “M”  22nd  Inf- 
Persons  Injured: 

Amwunition:  Lot  #172,  U.  S.  C~  1917. 

Nature  of  Faihre:  Barrel  failed. 

Probable  Cause:  Due  co  1 longitudinal  seam,  oe  lap,  in  the  metal  located  about 
7*A  inches  forward  of  the  butt  end  (^ringneld  Armory.) 

Disposition  of  Rifie:  Forward  co  the  ^ringneld  Armory. 


¥>4 


Hatcher’s  Notebook 


August  26,  1924. 


Rtpe  RIA  (Old  heat  treated  rccciva") 

Rtffert'nce:  O.  O.  600.91  j/ 1226,  1250 
Location:  l^lattsburg  Barracks,  N.  Y. 

Organhation:  Co.  “E"*  C.  M.  T.  C 

l‘crsom  Injured:  Candidate  Erlis  Mcaher,  above  organization,  slightly  injured, 
AvrwuTtition:  Lot  # 0-1424,  U.  S.  Cartridge  Co„  1918. 

Nature  of  Failure:  Receiver  blown  in  several  places.  The  explosion  caused  the 
receiver  lugs  the  rear  of  the  receiver  and  the  bole  to  be  blowji  from  ilic 
rifle  with  coiuiderahle  force. 

Vrobable  Cause:  Defective  ammunition.  Cases  arc  ovecamicaled  and  eunsc* 
ciuendy  liable  to  give  cut-offs  or  blown  heads  in  firing.  (Frankford  Arsc!iaU 
Failure  was  caused  primarily  by  a cartridge  ease  luving  a soft  head. 
Failure  of  rhe  head  subjecting  the  forward  end  of  the  receiver  to  gas 
pressure  sufficient  to  burst  It.  The  failure  is  typical  of  these  conditions  but 
IK  a somewhat  aggravated  case  due  to  the  receiver  being  rather  brittle. 
It  is  noted  that  this  ri£c  is  a Rock  Island  iiiannfacturc  and  that  its  re- 
ceiver had  been  given  a hear  treatment  as  used  for  rifles  up  to  the  number 
eight  hundred  thousand.  fSpriogncM  Armory) 
nispotirion  of  Rifle:  Forwarded  ro  the  Spring  held  Armory. 


Sept.  8,  1924. 

Ripe  No,  SA  78745 
Refer  Slice:  0.0.  474.1/4885 
Location:  Camp  Bullis,  Tcxa.s. 

Orgatinatirm: 

Versons  Injured: 

Anintunititm:  W.  R,  A.  Lot  #A-i  16. 

Nature  of  Failure:  Barrel  was  split  from  tlir  hrccch  to  a point  approtimacclv 
three  inches  ahead  of  the  forcing  cone.  Receiver  slightly  split,  (0.0.  Sen 
C A.) 

Vrobable  Ceuse:  Scam  in  barrel  caused  by  a “pipe.**  (Springfield  Armory) 
Disposition  of  Rifle:  ForvvanW«l  to  the  Springfield  Armof)*. 


Datc  — 1924. 

Rifle  No. 

Reference:  O.  O.  474.1/4800 
Location:  Ft.  McPherson,  Ga. 

Organization:  Co.  "A”  iind  Inf. 

Anmmnition: 

Nature  of  Failure:  Barrel  bulged  considerably  and  split  slightly  just  forward 
of  the  front  sight  stud. 

Vrobable  Cause:  Obstruction  in  the  lx>rc  (Springfield  Armory) 

Disposition  of  Rifle:  Forwarded  to  ilie  Sjiringfield  \rmory. 

Date  — 19x3. 

Rifle  No.  SA  1093941 
Reference:  O-  0,  474.1/4719 
Location:  Elgin,  Illinois 

Organhation:  Elgin  Rifle  Club.  415  Mill  Street,  Elgin.  Ill, 

Persons  Injured: 

A'frmomhifm:  F A 21-R 

Nature  of  Failure:  Bolt  lugs  set  back  about  i.<'64lh  inch  into  the  receiver.  Flange 
of  bolt  head  blown  oft.  (Springfield  Armoty) 

Vrobable  Cause:  Excessive  pressure  (Springfield  Annocy). 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory.  Rifle  replaced 
without  chaige  to  the  club  member. 


Rrcord  of  Accudckts 


465 


Oct.  27,  191J. 

Rifle  No.:  RIA.  250560 
R^erence:  0.0.  474.1/4709 
Location:  Fort  McPherson,  Ga. 

Organization: 

Persons  Injured:  One.  Slightly . 

Ammunition:  RA  Co.  Lot  #iiS. 

Nature  of  Failure:  Receiver  shattered,  'rhe  receiver  broke  off  clear  aroiin<l  even 
widi  the  end  of  the  rifle  barrel. 

Probable  Cause:  Due  to  soft  cartridge  case  or  excessively  high  pressure,  arc<Hii> 
panied  by  a brittle  reccii'cr.  (^ringfldd  Armory) 

Dis^sition  of  Rifle:  Forwarded  to  the  Springfleld  Armory. 


July  ir,  1923. 

Rifle  No,  2^4086 
Reference:  O.  O. 

Location:  Fort  Sill,  Oklahoma 
Organizeition:  Co.  “C”  179th  Inf.  Okla.  N.  G. 

Persons  injured:  Sergeant  Blair,  sillily  injured. 

Ammunition: 

Natter e of  Failure:  Receiver  failed. 

Probable  Cause:  The  indications  are  that  failure  of  the  receiver  was  due  to  the 
combiiiatjou  of  excessive  headspace  and  a brittle  receiver,  possibly  aggravated 
by  a soft  case  or  excessive  pressure  or  both.  (Springfleld  Armory) 
Disposicion  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


July  24,  1923. 

Rifle  No.  655360 

Reference:  O.  O.  474.1/4677,  O.  O.  47141/2037.  2057,  2058 
Location:  State  Cairw,  Peel^ill.  N.  Y. 

Organization:  14th  mf.  N.  Y.  N.  G. 

Persons  Injured:  One.  Slishdy. 

Ammtenition:  W.  R.  A.  Co.,  l^e  A-364. 
feature  of  Failure:  Barrel  burst. 

Probable  Cause:  No  defect  in  rifle.  Caused  by  an  obstruction  in  the  bore. 
(Springfleld  Armory) 

Disposition  of  Rifle:  Forwarded  to  the  ^ringfleld  Armory. 


May  9,  J92J. 

Rifle  No.  SA  642742 
Reference:  O.  O.  471.41/1082 
Location:  Hawaiian  Department. 

Organkathn:  Co.  35th  Inf. 

Persons  Injured:  Private  Manley,  above  organization,  seriously  inj tired,  losing 
his  right  eye. 

Ammunition:  u.  S.  Cartridge  Co.,  Lot  D-1410 

Nature  of  Failure:  Top  of  the  receiver  blown  off.  It  is  probable  dtat  riic  receiver 

Sve  way  over  the  direaded  section  of  the  barrel  first.  (D.O.O.  Hawaiian 
eptn  Maj.  W.  L.  Oay) 

Probable  Cause:  Excessive  headspace  and  insufficient  strength  and  ductili^  of 
the  receiver  acemnpanied  by  unusuallv  high  pressure.  Examination  or  the 
fracture  of  the  receiver  show  a complete  lack  of  ductilicy  and  a condrtiMt 
not  suited  to  withstand  the  pmure  exerted  oa  die  face  of  the  bolt  in 
abnormal  cases  produced  by  excessive  headspace  or  undue  high  chamber 
pressure,  (^ringfield  Armory) 

Disposition  of  nifle:  Forwarded  to  the  Springfield  Armory. 


^66 


Hatcher’s  Notebook 


May  iS,  1933* 

Rifle  No.  SA  1254701 
Reference:  O.  O.  600^23/948 
Location:  West  Pointy  N.  Y. 

Organizar/on:  U.  S Miliiary  Aca<)eniy. 

Persons  Injured:  None. 

Anmtumtion:  W.  R.  A.  Co.  Lot  A-J77- 

Nature  of  Failure:  Barrel  bum  at  powder  diaa^ber. 

Probable  Cause:  Burot  metal  in  the  buR  section  of  the  barrel.  (Springfield 
Armory) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


June,  1924* 

Hific  No.  RIA  90iot 

Reference:  0.  O.  474.1/4863,  4884 

Location:  Camp  Stephen  D.  Little,  Nogales,  Arizona. 

Organization:  Co.  “P’  25^  Infantry. 

Persons  injured: 

Anmunition:  W.  R,  A.  Co.,  Lot  A-435 

Nature  of  Failure:  Barrel  ^Itt  about  nve  inches  from  d)e  mu  fide. 

Probable  Cause:  Failure  of  the  barrel  was  caused  by  a seam  which  evidently  did 
not  sliow  in  mamifacnire.  (Sprin^eld  Armory.) 

Disposition  of  Rifle:  Forwarded  to  Springfield  Armt>ry. 


April  30,  1923. 

Rifle  No,  RIA  104926 
Reference:  O.  O.  600.913/9^,  1094 
Locatim:  Fort  Wm.  McKinley,  P.  I. 

Organization:  Co.  “G”  31st  Infanay. 

Persons  Injured:  Major  Heisii^oo,  31st  Inf.  Seriously. 

Ammunition:  U.  S.  C Co.,  Lot  D-iioo,  Powder  Lot  9S3  B io39>to58 
Nature  of  Failure:  The  barrel  and  receiver  of  this  rifle  were  separated  at  the 
place  they  screw  together.  The  barrel  appeared  to  be  unbjured  but  the 
Receiver  •was  blown  all  to  pieces.  Tbc  bolt  was  picked  up  about  twenty 
paces  to  the  right  and  was  slightly  bent.  The  loclung  lugs  and  safety  lugs 
showed  that  they  were  subjected  to  an  enormous  pressure.  (Procec<lings. 
Board  of  OiFcers.) 

Probable  Cause:  The  cause  of  failure  in  this  case  lies  in  the  weakness  nf  the 
receiver  under  abnormal  conditions.  It  is  quite  possible  cliat  a receiver  of 
recent  manufacture  would  have  held  under  the  same  cunditinn.s,  Receiver 
doe.<$  not  possess  the  ducdlky  desired  and  Stained  by  the  latest  method  of 
heat  treating.  (Extract  from  Repwt  oi  Springfield  AniKiry) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


May  I,  1923. 

Rifle  No.  SA  523089 

Reference:  O.  O.  600.913/970,  1094 

Location:  Fort  Wm-  McKinley,  P.  I. 

Organization:  Co.  “C”  31st  Infantry. 

Persons  Injured:  None. 


Record  of  Accidents 


467 


Amnmnition:  U.  S.  C.  Co.,  Lot  D*iioo,  Powder  Ix>c  985  B 1059-1058. 

Mature  of  Failure:  Rear  sight  blow*n  off.  Fixed  base  split  longitudinally  about 
two  inches  the  movable  base  was  forced  upward  about  ifx  center  mid  broken 
in  half.  (Proceedings  of  .i  Board  iif  Officers)  Barrel  split  about  tme-incli 
Jong  immediately  under  the  fixed  base  of  die  rear  sight.  (Springfield 
Armory). 

Probable  Cmsc:  Metal  iu  the  liarrel  when  polished  indicating  that  the  metal 
is  burnt,  so  weakening  the  barrel  that  the  acculent  followed.  (Springfield 
Armory). 

Disposition  of  Rifle:  Forwarded  to  the  Sprinficld  Armory, 


May,  19:4. 

Kjfle  No. 

Re)erence:  0.0.  <500.915/1*51 

Location:  Dona  Ana  Tai^ci  Range,  N.  M. 

Organization:  isr  S<jd.  7th  Cavalry. 

Versons  Injured:  Sgc.  Rufus  O.  Ervin,  Troop  “C/*  7th  Cav.  Slightly. 

Anmtunition:  W.  R.  A.  Co.,  Lot  #453 

Nature  of  Failure : Bole  blown  from  rifle.  Receiver  ruplurtil. 

Probable  Cause:  I inspected  »vm’s  rifle  after  the  accident,  the  steel  of  the 
receiver  appeared  brittle  and  cryscalired.  Witness  scared  to  me  that  one 
of  the  upper  holding  hags  of  the  bolt  was  broken.  This  bolt  could  not  be 
found  for  presentation  as  evidence,  when  1 iavestigared  this  case.  (Major 
R.  H.  Lee,  Ord.  Dept.,  Post  Ordnance  Officer  testifying  before  a Board  of 
Officers.) 

Disposition  of  Rifle: 


Sept.  13.  19:4. 

Rifle  No,  aaSm 

Reference:  O.  O.  600.91 3/j  253 

Location:  Bay  Range,  Fon  Humphrie,  Va. 

Organization:  Co.  “A”  13th  Engineers, 

Persons  Injured:  None. 

Anmnenition:  F.  A.  Lot  #449  of  1917. 

Nature  of  Failure:  Burst  receiver. 

Probable  Cause:  An  esianiinauon  of  the  damaged  rifle  indicates  that  the  accident 
touk  place  just  as  tlie  lockup  lugs  on  tlic  bolt  were  beginning  to  engage 
with  the  corresponding  locking  shoulden  on  the  receiver.  The  bolt  was 
recovered  after  the  accident  and  it  was  found  that  the  firing  pin  was 
protruding  from  the  face  of  the  bolt  and  was  stuck  fast  in  that  position. 
I'hese  circumstances  appear  to  indicate  that  the  firing  pin  was  damaged  by 
the  shot  fired  previous  10  the  one  which  disrupted  the  rifle  and  that  it  was 
protruding  from  the  bolt  in  such  a manner  that  it  fired  the  cartridge  before 
the  liLilt  W2.S  fully  locked  2s  it  was  being  pushed  into  the  chamber  during  rhe 
operation  of  loadir^.  (Sub-Committee,  ITie  Ordnance  Committee,  Tech. 
Staff,  Jan.  22,  1925 -) 

Disposition  of  Rifle: 


Oct.  28,  1924. 

Rjfle  No.  90489 

Reference:  O.  0.  60091 3.''! 305 

Location:  Fort  Washington,  Md. 

Organization:  Co.  "K”  12th  Inf. 

Persons  Injured:  None. 

Ammunition:  F.  A.  E.  C Powder,  Lot  No.  5 (blank) 


Hatgh£r's  Notebook 


468 

Nature  of  Failure:  Barrel  jqjlit  ittmi  cliamber  t<i  tlie  upper  baud. 

Frobable  Cause:  During  tactical  exercise  Private  Jones  was  advancing  from  one 
one  position  to  another  and  it  is  thought  die  muzzle  of  the  rifle  accidenrly 
sirucK  the  ground  thus  fouling  the  bcffe.  (O.  O.  Fort  W'ashingron) 
Disposition  of  aifle: 


Dec.  5,  1914. 

Rifle  No.  SA  642^75 

Reference:  O.  O.  474.1/4915,  4932,  O.  O.  600-913/1521 
Location:  Hawaiian  Department. 

Orgamzation:  Co.  ‘‘G’'  35th  Inf. 

Persons  Injured:  Private  James  C.  Pickett,  35th  Inf.  Seriously. 

Anmrunition:  U.  S.  Cartridge  Co.,  Lot  No,  D'1437. 

Nature  of  Failure:  Recehser  shattered.  Tup  blown  completely  otf.  Cracked  at 
jimcri^in  with  ^iarr«)  in  k>wcr  half.  Bolt  was  blown  to  reac  ^licariiig  safety 
stop  on  receiver.  No  evidence  of  obstruction  in  bore.  (Major  James  Kirk; 
Probable  Cause:  Excessive  pressure  and  brirde  receiver.  (Springfield  Armtiry; 
Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


Feb.  26,  1915. 

Rifle  No.  SA  468300 

Reference:  0.  0.  600.913/1342.  1356,  1393 
Lfjcasirm:  Camp  f«wis,  Washington. 

OrgofUzation:  Co.  "A,”  6th  Engineers,  3rd  l>iv. 

PersoTU  Injured:  Two  enlisted  men  injured. 

Armnmiiion:  Firing  rifle  grenades,  Lacltrynucory.  C N.,  Lot  7*27-22.  Blank 
Ammanicion  used. 

Nature  of  Failure:  Receiver  demolished. 

Probable  Cause:  Failure  resulted  from  a britsU  receiver  subjected  to  high  gas 
pressure  by  failure  of  rhe  cartridge  head.  (Springfield  Antmry) 

Disposition  of  Rifle:  Forwarded  to  the  Springfleid  Armory. 


March  4,  1925* 

Rifle  No.  SA  193082 
Reference:  O.  0.  600.913/1361/1383 
Location:  Fort  Wm.  McKinley.  P.  L 
Organization:  Headquarters  Company.  ji«  Infantry, 

Persons  Injured:  Four,  Slightly. 

Artmtunition:  U.  S.  Cartridge  Co.,  Lot  No.  978 
Namre  of  Failure:  Receiver  shattered.  Bolt  blown  out. 

Probable  Cause:  Excessive  cliaiuber  pressiin;  an<l  brittle  receiver  . . . Metal  of 
coarse  structure  ...  If  properly  heat  treated  and  tough,  the  receiver  is  nor 
likelv  to  shatter  alrbough  it  is  almost  cerrain  to  be  split,  bat  a brittle 
receiver  will  invariably  shatter.  (Springfield  Artnory) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


March  20,  1925. 

Rifle  No.  SA  613496 
Reference:  O.  O.  474.811/260 
Location:  Fort  Sill,  Oklahoma 
Organization:  Co.  “F’  20th  Infantry. 

Persofis  Injured:  None. 

Ammunition:  'I'racer.  Lot  number  not  known. 

Nature  of  Failure:  Barrel  burst. 


Record  ok  Accidf.vts 


469 

Frobable  Cause:  The  evidence  indicates  due  the  soldier  who  had  the  ride  was 
iirlng  tracer  ammunition  when  one  round  failed  to  explode  properly,  causing 
the  bullet  to  lodge  in  the  bore  about  six  inches  from  the  muzzle.  The 
snldier  did  not  investigate  the  iiialf unction,  particularly  tn  determine  whether 
the  bore  was  clear,  consequendy  on  die  next  shot  the  barrel  burse.  (Major 
A.  J.  Stuart,  Ord.  Dept.) 

Disposition  of  Rdfie:  lurned  in  locally  for  exchange. 


April  24,  1925. 

Rifle  No.  206331 

Reference:  Q.  O.  600.91 3/1 3S4,  1410,  1446 

Location:  Fort  Huachuca,  Arizona 

Organization:  tsc  Sqd.  iodi  Cavalry. 

Persons  Injured: 

Ammunition:  Peters  Cartridge  Co.,  I.nt  No,  A-139. 

Nature  of  Failure:  Receiver  sbettered.  Tlie  receiver  was  sheared  off  at  the  bolt 
(ticking  lug  recess  on  the  lower  side  of  the  receiver  in  a dotvnward  backward 
direction.  *lhe  left  side  of  the  receiver  ajgo  fractured  at  the  base  of  the 
safety  shoulder.  The  right  tide  of  the  receiver  was  fractured  underneath 
and  to  the  point  c<^ual  to  the  rear  face  of  the  cut-off  thumb  piece.  The  top 
portion  of  tne  receiver  both  front  and  rear  when  fractured. 

Frooable  Cause:  The  failure  of  the  above  metuioned  ri£c  was  undoubtedly  due 
primarily  to  the  breaking  out  of  the  cartridge  head.  This  is  the  result  of 
a weak  or  soft  cartridge  head,  excessive  head  space  due  to  setting  back  of 
the  bolt  or  to  a combinadon  of  both  of  these.  The  receiver  was  one  of 
the  earlier  single  heat  treated  type  any  of  which  arc  almost  certain  to 
shatter  when  the  cartridge  head  faiW.  (Springfield  Armory). 

Disposition  of  Rifle:  Forwarded  to  tlie  Sfinngl^ld  Annory. 


May  :i.  1925. 

Rifle  No.  SA  523444 

Reference:  0.0.  ^.913/1442,  1444,  1454. 

Location:  Fore  Wm.  McKinley,  Rizal,  P.  L 
Organization:  Co.  15th  Infantry. 

Persons  Injured:  None. 

Amrmmition:  Western  Cartridge  Co.,  Lot  # S*J5. 

Nature  of  Failure:  Portion  of  tlie  barrel  3"  long  and  one-half  the  circumference 
was  blown  away. 

probable  Cause:  Barrel  failed  because  the  steel  was  burned  during  manufacture 
of  the  barrel  blank.  (Springfield  Armory) 

Disposition  of  Rifle:  Forwarded  to  the  Sprir^field  Armory. 


June  5,  1925. 

Rifle  No,  RIA  170805 
Reference:  O.  O,  600.913/1440,  1441 
Location:  Fort  Wm.  McKblcy,  Rizal,  P.  L 
Orgamzation:  Co,  “C”  14th  l^gineen,  P.  S. 

Persons  Injured:  Staff  Sgr.  Felix  Armada,  Sighdy. 

Ammunition:  U.  S.  Cartridge  Co.,  Lot  No.  744. 

Nature  of  Faiiure:  Upper  &onc  locking  Lug  stripped.  Upper  front  face  of  bolt 
fractured.  Top  of  receiver  containing  Ae  seri^  number  blown  off.  The  bolt 
was  picked  up  off  the  gmnud  directly  under  the  rifie.  (Capt.  David  W. 
Craig,  Ord.  Dept.,  O.  O.  Fort  McKinley.) 

Probable  Cause:  Defective  ammunition  and  receiver  of  old  heat  treatment. 
(Record) 

Dfsposithn  of  Rifle:  Forwarded  to  the  Spnc^eld  Armory, 


470 


Hatcher’s  Notebook 


June  10,  *925. 

Rifle  No,  RIA  146554 

Reference:  O.  O.  600.913/1400,  1407,  1408 

Location:  Camp  McClElian,  Ala. 

Organization:  Co.  “A,”  22nd  Infaocry. 

Versons  Injured:  Private  Q)arlcs  A.  Vick,  above  orgai;ization»  slightly, 

Ammunition:  Peters  Cartridge  Co.,  Lot  K*i,  1918  Grade  E. 

Nature  of  Failure:  Receiver  blown  to  piecess.  Bolt  an<l  pieces  of  receiver  were 
found  twenty  steps  from  where  the  rifle  exploded.  (O.  O.  22nd  Inf.  Camp 
McClellan,  AJa.) 

Vro  table  Cause:  An  examination  of  barrel  and  ruptured  case  would  seem  to 
indicate  that  the  misfired  case  was  withdrawn  from  the  chamber,  leaving 
the  bullet  in  the  bore.  The  next  cartridge  was  forced  on  to  the  bullet, 
seating  the  bullet  onto  the  powder  charge.  This  with  the  added  resistance 
of  the  first  bullet  caused  sufficient  pressure  to  blow  up  the  riile.  The 
excessive  shattering  was  due  to  the  receiver  being  of  the  old  single  heat 
treatment.  (Spring^cld) 

Disposition  of  Rifle:  Forwarded  to  the  Springfield  Armory. 


Ang.  Tj,  1925. 

Ripe  No.  SA  858256 

Reference:  O.  O,  600.91 3/1465,  1496 

Location:  Fort  Ruger,  T.  H. 

Organization:  Hdq.  Det.  & C<  T.,  2nd  Bat.  55th  C.  A. 

Persons  injured:  None. 

AmntJtnhion:  Reloaded  galleiy  practice. 

Nature  of  Failure:  Barrel  split  and  bulged. 

Probable  Cause:  Obstruction  in  the  Barrel.  (Springfield  Armory) 

Disposition  of  Rifle:  Forwarded  to  tlte  Springfield  Armciy. 


Date  — 1915. 

Rific  No,  SA  1004623 

Reference:  0.  O.  474.1/5090 

Location:  U.  S.  Naval  Academy,  Annapolis,  Md. 

Organization:  U.  S,  Navy, 

Persons  injured:  None. 

Ammunition:  Remi^on,  V.  S.  .M.  C Co.  Lot  E»m4.  Manuf.  Nov,  23,  191B, 
Nature  of  Failure:  Barrel  split  under  the  fixed  l>ase  sight  band,  showing  a crack 
starting  about  two  inches  forward  of  the  receiver  and  extending  longitudinally 
towards  the  muzzle  for  about  inches.  (Navy  Dept.,  Bureau  of  Ordnance) 
Probable  Cause:  Defective  heat  treatment.  (Springfield  Armory.) 

Disposition  of  Rifle:  Forwarded  to  tbe  Spriugfield  Armory. 


Oct.  27,  1925. 

Rrfic  No.  SA  1198207 
Reference:  O.  O.  600.913/1499,  1521 
Location:  Fort  Bcnning,  Ga. 

Organization:  FiiW  by  recruits.  Hqs.  Co.,  2nd  Bat.  29th  Inf. 

Persons  Injwed:  Two.  Sightly. 

Ammunition:  Unknown.  <0.  O.  Fort  Benning) 

Nature  of  Failure:  .Magazine  fioor  plate  and  nring  pfa  rod  were  blown  out  and 
stock  was  broken  on  both  rides  opposite  magarine.  (O.  O,  Fort  Benning) 
Probable  Ca